PCB design can feel like solving a Rubik’s cube with your eyes closed—one small mistake can send your whole project off course. Fortunately, there are plenty of ways to avoid the most common pitfalls. This guide takes you through the 10 most widespread PCB design mistakes and gives you concrete solutions to take your design from “almost good” to “works every time”.

If you feel overwhelmed along the way, remember: you can always get help from our experienced team through our consulting department. We are ready to help you all the way from idea to finished product!

1. Forgetting Impedance Control

High-speed signals, especially in USB or RF designs, require precise impedance control. Ignoring it risks signal distortion and loss.

How to Avoid It:

• Use PCB stackups with defined dielectric materials.
• Calculate trace width and spacing for differential pairs using tools such as Altium Designer or online calculators.
• Ensure all critical signals have smooth trace routes without unnecessary bends or vias.

2. Incorrect Decoupling Capacitor Placement

Decoupling capacitors are small but essential for reducing noise and maintaining stable power. Incorrect placement can lead to unstable circuits.

How to Avoid It:

• Place decoupling capacitors as close as possible to IC power pins.
• Use several capacitors with different values (e.g. 0.1 µF and 10 µF) to cover different frequencies.

3. Too Many Vias on Signal Traces

Every time a trace changes layers through a via, it creates a discontinuity that can impair signal integrity, especially at high speeds.

How to Avoid It:

• Plan your layout to minimise layer changes.
• Use microvias or blind/buried vias where necessary in complex designs.

4. Inadequate Thermal Management

If heat dissipation is inadequate, components can overheat, reducing your device’s lifespan and reliability.

How to Avoid It:

• Use thermal vias under high-power components such as power regulators.
• Add copper areas (pads) for better heat dissipation.
• Consider active cooling or heat sinks in critical designs.

5. Overcrowded Layouts

An overcrowded layout can cause crosstalk between signals and make troubleshooting a nightmare.

How to Avoid It:

• Keep high-speed traces away from noise-sensitive areas.
• Reserve space for ground shielding and ensure good separation between signal types.

6. Poor Ground Plane Management

An inconsistent or broken ground plane can cause noise and signal distortion.

How to Avoid It:

• Use a solid ground plane without unnecessary holes or gaps.
• Ensure the shortest possible return path for critical signals.
• Avoid “flying ground traces” that can act as antennas.

7. Incorrect Trace and Pad Sizing

Traces or pads that are too thin can lead to overheating and poor reliability, especially on power supply lines.

How to Avoid It:

• Use a trace-width calculator to size traces for the current.
• Ensure pads are large enough for reliable soldering and mechanical strength.

8. Missing DFM (Design for Manufacturability)

A design that ignores manufacturing processes can be expensive or impossible to produce.

How to Avoid It:

• Follow the PCB manufacturer’s recommendations for trace spacing, layer thickness and vias.
• Test your design with DFM checking tools.

9. Ignoring Electromagnetic Compatibility (EMC)

Poorly designed PCBs can emit EMI, causing certification problems and malfunctioning devices.

How to Avoid It:

• Use shielding (ground planes, grounded enclosures) to reduce EMI.
• Keep high-frequency signals short and away from other signals.
• Use ferrite beads or EMI filters where necessary.

10. Poor Documentation

Even the best PCB design can become problematic without proper documentation. Your future self (or colleagues) will thank you for doing it properly.

How to Avoid It:

• Make sure your design includes up-to-date component placements, a netlist and production files (Gerber, BOM, etc.).
• Document critical design decisions, such as trace widths and impedance requirements.

Conclusion

PCB design requires a balance between theory and practice. By avoiding these 10 mistakes and implementing the right solutions, you can ensure your design works reliably and is ready for production.

If you run into challenges, we are ready to help! At eBits.dk, we offer professional advice through our consulting department. Whether you need help with design, manufacturing or troubleshooting, we have the experts to guide you successfully to your goal.

And remember: PCB design is like building LEGO—once you understand the pieces, it becomes both fun and satisfying. 🚀