While these operations can be accomplished with ultrasonic machining, rotary tooling/end milling (Handheld or CNC), EDM, lasers and grinding equipment, PMP is often much faster—not just in producing the part, but also in the time it takes for setup.
PMP Limitations
There are limits to what PMP can do.
Although metals and plastics can be surface engraved or marked, they cannot be machined deeply with PMP due to their inherently ductile nature. PMP does work well, however, to selectively remove thin layers (<.005”) of these materials such as copper-clad substrates or metal encapsulated ceramics.
Etching produces a tapered side wall as the etch deepens due to the build-up of abrasive in the etched cavity. This build-up causes the sides of the feature to etch more slowly than the center leaving the bottom of the etch area with a slight radius. NOTE: For through-holes in some materials, etching can be done from both sides to help straighten sidewalls. In thicker materials, this may produce an hour-glass effect which may be beneficial in certain applications.
Precision etch depth control will require an automated etching system, although manual etching will typically yield tolerances of +/- 0.002". |
