Common PCB design mistakes - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Identifying a common PCB layout mistake

Which of the following is a common mistake when placing components on a PCB?

A Placing components too close to each other causing soldering issues

B Using a ground plane to reduce noise

C Routing power traces with sufficient width

D Adding test points for debugging

💡 Hint

Think about what might cause manufacturing or reliability problems.

Placing components too close can cause solder bridges and assembly problems, which is a common PCB design mistake.

🎯 Scenario

intermediate

Troubleshooting signal integrity issues

You notice signal integrity problems on a high-speed PCB. Which design mistake is most likely causing this?

A Using controlled impedance traces

B Placing decoupling capacitors close to IC power pins

C Using long, unshielded traces with many vias

D Implementing proper differential pairs routing

💡 Hint

Consider what affects signal quality and timing on high-speed signals.

Long traces with many vias can cause reflections and signal degradation, leading to signal integrity issues.

🔧 Formula Fix

advanced

Identifying the cause of power noise

Which mistake in PCB power design can cause excessive noise on the power rails?

A Using a solid ground plane

B Not placing enough decoupling capacitors near ICs

C Routing power traces with wide copper areas

D Separating analog and digital grounds properly

💡 Hint

Think about what helps stabilize power supply voltage at the IC.

Insufficient decoupling capacitors cause voltage fluctuations and noise on power rails.

❓ visualization

advanced

Visualizing a PCB trace routing mistake

Which of the following trace routing patterns is a common PCB mistake that can cause EMI problems?

A Differential pairs routed closely with matched length

B Short, perpendicular crossing traces

C Ground traces surrounding signal traces

D Long parallel traces running close together for a long distance

💡 Hint

Think about what causes electromagnetic interference between traces.

Long parallel traces close together can cause crosstalk and EMI issues, a common PCB design mistake.

❓ data_modeling

expert

Modeling PCB layer stackup for signal integrity

Which PCB layer stackup mistake can degrade signal integrity in a high-speed design?

A Placing signal layers adjacent to each other without a ground plane in between

B Including a solid ground plane next to signal layers

C Using alternating signal and ground planes

D Using controlled impedance layers with proper dielectric thickness

💡 Hint

Consider how return current paths affect signal quality.

Signal layers adjacent without a ground plane cause poor return paths and degrade signal integrity.