PCB Manufacturing

Etching defines what your PCB layout can and cannot achieve. Understanding the relationship between copper thickness, trace width, and spacing is not optional — it directly affects what your board costs and who can make it. How Etching Works — Downward and Sideways # The etchant does not only remove copper downward. It simultaneously attacks laterally — inward beneath the etch resist at the edges of every copper structure. This lateral attack is called undercut. The etch medium itself can be alkaline or acidic depending on the process — both attack copper selectively through the use of photo and metal resists as protective layers.

One of the most persistent misconceptions about PTFE-based PCB laminates comes from handling the material. Pick up a sheet of Rogers RO4350B or RT/duroid 5880 and compare it to a sheet of standard FR4. The PTFE laminate feels different — slightly softer, with a quality that engineers sometimes describe as rubbery or compliant. Bend it gently and it flexes slightly before springing back. This tactile impression leads directly to a dangerous assumption: that PTFE can be used in flexible PCB applications, or treated with more mechanical freedom than a rigid board.