13 Common PCB Problems & How to Fix Them in Altium

Here’s a practical guide to 13 common PCB problems in Altium Designer and how to fix them, covering design, layout, and manufacturing issues:

1. Unrouted Nets

  • Problem: Airwires (ratsnest lines) after autorouting or manual routing gaps.

  • Fix:

    • Use Route → Un-Routed Connections to highlight missed nets.

    • Enable Real-Time DRC (Design Rule Check) to catch unconnected pins.

    • Run Tools → Design Rule Check and review "Un-Routed Net" violations.

2. Design Rule Violations (DRC Errors)

  • Problem: Clearance, width, or solder mask errors.

  • Fix:

    • Open Design Rules (D → R), adjust constraints (clearance, via sizes).

    • Use PCB Rules and Violations panel to navigate errors.

    • Right-click violations → Violation Details to locate issues.

3. Missing Footprints

  • Problem: "Footprint Not Found" when importing schematics.

  • Fix:

    • Ensure libraries are installed/enabled (Preferences → Data Management).

    • Use Tools → Update From Libraries to sync footprints.

    • Manually assign footprints in PCB Library or via Component Panel.

4. Silkscreen Overlaps Pads

  • Problem: Text/legends touching solder pads (causes assembly issues).

  • Fix:

    • Enable Component Silkscreen Clearance Rule in Design Rules.

    • Use Tools → Arrange → Reposition Selected Components to auto-adjust text.

    • Manually drag silkscreen text away from pads.

5. Incorrect Net Connectivity

  • Problem: Nets don’t match between schematic and PCB.

  • Fix:

    • Run Design → Update PCB Document to sync changes.

    • Use Projects → Show Differences to compare schematic/PCB.

    • Check for duplicate net names or missing ports in the schematic.

6. Copper Slivers (Manufacturing Risk)

  • Problem: Thin, isolated copper traces that can detach during etching.

  • Fix:

    • Run Tools → Design Rule Check → Manufacturing → Copper Sliver rule.

    • Use Polygon Manager (T → G → M) to adjust copper pour settings.

    • Increase minimum copper width in Polygon Connect Style rules.

7. Starved Thermal Pads

  • Problem: Inadequate thermal relief connections for pads/polygons.

  • Fix:

    • Adjust Polygon Connect Style rule for thermal relief width/spokes.

    • Select polygon → Properties → Thermal Relief settings.

    • Use Relief Connect for large pads, Direct Connect for small pads.

8. Acid Traps (Sharp Angles)

  • Problem: Acute-angle traces (<90°) trap etching chemicals.

  • Fix:

    • Enable Acute Angle rule in Design Rules → Manufacturing.

    • Use Route → Interactive Routing with Shift+Space to switch corner styles.

    • Replace sharp angles with 45° or curved traces.

9. Missing Solder Mask Between Pins

  • Problem: Solder mask web too thin or missing, risking solder bridges.

  • Fix:

    • Set Solder Mask Expansion rule (Design Rules → Manufacturing).

    • Adjust Solder Mask Sliver rule to ensure minimum mask between pads.

    • Verify in 3D Viewer (3) or output Solder Mask Gerber.

10. Via-in-Pad Without Tenting

  • Problem: Vias in SMD pads w/o tenting cause solder wicking.

  • Fix:

    • Enable Tenting in via properties (double-click via → "Tented" option).

    • Add Solder Mask Override rule for specific vias.

    • Use Via Shielding or plug vias with epoxy fill (for high-density designs).

11. Incorrect Layer Stackup

  • Problem: Impedance mismatch or manufacturing issues.

  • Fix:

    • Open Layer Stack Manager (D → K), verify dielectric thickness/materials.

    • Use Impedance Profile tool to calculate trace width for target impedance.

    • Export Stackup Report for manufacturer validation.

12. Outdated Library Components

  • Problem: Old footprints with incorrect pad sizes or courtyard outlines.

  • Fix:

    • Use Library Migrator (File → Library Migrator) to update libraries.

    • Generate new footprints with IPC Compliant Footprint Wizard.

    • Cross-check with manufacturer datasheets.

13. Gerber/DXF Export Errors

  • Problem: Missing layers, incorrect scales, or alignment issues.

  • Fix:

    • Use File → Fabrication Outputs → Gerber Files with RS-274X format.

    • Enable Include unconnected mid-layer pads for multilayer boards.

    • Generate NC Drill Files separately and verify with Gerber Viewer (e.g., GC-Prevue).

Pro Tips for Prevention:

  1. Use Templates: Save validated rule sets and layer stackups as templates.

  2. 3D Model Integration: Check mechanical fit with MCAD collaboration.

  3. Version Control: Use Altium 365 or Git to track changes and revert if needed.

#Altium #PCBDesign #Electronics #DesignRules #DFM #Engineering #HardwareDesign #Troubleshooting

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