Due to these traps, the desired copper feature starts to erode (over- etching), creating an ‘open’ or lost connection. It happens before washing when residual acid gets collected in these trap areas and not cleared away. If any copper feature is bending anywhere below 90 0 (acute angle), it may act as an acid trap during PCB fabrication. To define acid traps, we need to know how traces are laid on the PCB surface. Keeping track of DFM rules and consistent DFM checks can help the designer to avoid the following DFM issues: 1.
Companies use specific DFM tools and DFM software based on their design requirement. DFM issues are related to the PCB geometry, and most of the time, go undetectable during the DFM checks.
And, sometimes even the changes made are not on the same page with the design and its performance or electrical requirements.ĭFM analysis identifies the PCB layout issues that can create manufacturing problems during assembly and fabrication. But very often, manufacturers do not intimate designers about the changes they made. It’s true that manufacturers use DFM checks to look for issues and fix them. That would be a nightmare! DFM is not only a manufacturer guide to better fabrication and assembly but can also help designers. Imagine finding DFM issues in the fabrication and assembly process in the final stage.
What is design for manufacturability or DFM in a PCB?ĭFM for PCB is a set of design guidelines that attempt to ensure its manufacturability.