1. Key Risks to Watch For

• Thermal issues: Components that generate heat (like voltage regulators, LEDs, or power ICs) need space to dissipate. If they’re packed too tightly, heat builds up—leading to component failure or reduced lifespan. For example, a LED array laid out without gaps between diodes might dim prematurely, as excess heat degrades their performance.
• Signal noise: High-speed signals (such as USB 3.0, Ethernet, or RF) are sensitive to interference from power traces. Running these signal traces parallel to power lines, or placing them too close to noisy components (like motors or relays), can corrupt data—causing glitches in communication or sensor readings.

• Trace width mistakes: Using a trace that’s too thin for high-current paths (e.g., power inputs for motors) leads to voltage drops and overheating. A 0.2mm trace, for instance, can only handle around 0.5A of current; using it for a 2A motor will result in the trace overheating and possibly burning out.
  

2. 3 Practical Rules for Smooth Layout

• Group components by function: Keep power components (regulators, capacitors, batteries) in one area, and signal components (sensors, microchips, communication modules) in another. This separates noisy power paths from sensitive signals, reducing interference. For a temperature sensor board, for example, placing the 5V regulator far from the sensor IC ensures the sensor’s readings stay accurate.
• Optimize trace length and routing: High-speed signals need short, direct traces. For differential pairs (like HDMI or CAN bus), both traces must be the same length—even a 1mm difference can cause signal skew, breaking communication. For low-speed signals (like a simple button input), trace length is less critical, but keeping it short still reduces noise.
• Use Design Rule Check (DRC) early: DRC tools flag issues like trace-to-trace spacing violations, too-thin traces, or missing ground connections. Run DRC after finishing each section (e.g., power path, signal path) instead of waiting until the end. This catches small mistakes early—fixing a spacing error takes minutes, but reworking an entire board because of it wastes hours.

3. The Most Common Mistake to Avoid