Designing a PCB with the DEX PCB Designer > Designs > Parts

The phrase "Don't Trust Part Libraries" is a common mantra among experienced electronics designers, especially those involved in PCB (printed circuit board) design. The reason behind this cautionary phrase is that relying solely on pre-existing part libraries without verification can lead to costly mistakes. Here's why designers advocate for this cautious approach:

•Mistakes in Libraries: Even the best libraries can contain errors. This could be a wrong footprint, incorrect pin assignment, or any number of other possible issues.

•Outdated Libraries: Components get updated by manufacturers, and libraries might not reflect the most recent version.

•Variability in Standards: Different manufacturers might have slightly different recommendations for land patterns or footprints for the same component.

•Specific Requirements: A generic footprint from a library might not meet specific needs, such as a particular soldering process or thermal requirements.

•Lack of Comprehensive Data: Some libraries might provide footprints but lack schematic symbols or 3D models.

•Consistency: When working on a team or on multiple projects, having consistent naming conventions and organization can be crucial. Relying on external libraries can introduce inconsistency.

•Verification: Even if a part library is correct, it's a good practice to verify the footprint and schematic symbol against the component's datasheet. This step ensures that the component will fit correctly on the PCB and function as expected in the circuit.

•What to Do Instead?

•Verify Everything: If you decide to use a part from a library, always cross-check it against the manufacturer's datasheet.

•Build Your Library: Over time, create and maintain a personal or company-specific library of components that have been verified and used in successful projects.

•Use Library Tools: Some advanced PCB design software offers tools that can automate the process of checking and verifying footprints and schematic symbols.

•Collaboration: If working in a team, collaborate and have peer reviews of new library components. Two eyes are always better than one.

•Stay Organized: As you add to your library, keep it organized. Proper naming conventions, categories, and clear version control can save a lot of headaches in the long run.

•Backup and Version Control: Ensure that your libraries are regularly backed up and that there's a system in place for version control.

In conclusion, while existing part libraries can save time and provide a valuable starting point, it's essential always to verify each part's details. This approach ensures the reliability and functionality of the final PCB design.