How does a PCB mill work?
Printed circuit board milling (also: isolation milling) is the process of removing areas of copper from a sheet of printed circuit board material to recreate the pads, signal traces and structures according to patterns from a digital circuit board plan known as a layout file.
What is End Milling?
End milling is a type of milling process that can be used to produce slots, shoulders, die cavities, contours, profiles, and other milling parts. End milling uses the end mill which is a cylindrical cutter with multiple cutting edges on both its periphery and its tip, permitting end cutting and peripheral cutting.
End Mill Coatings
Endmills with added chemical coatings are also popular today.
Often more expensive, these coatings are added to the bit to reduce wear and friction. However, not all coatings are suitable for all materials and whilst a particular coating may be good for productivity on one material, it may be not be on another.
Popular coatings are Aluminum Titanium Nitride (AlTiN) and Titanium Diboride (TiB2).
Troubleshooting Tips for working with End Mills
- Selecting the right tooling for your material and project will improve the quality of your work and reduce the need for excessive hand-finishing.
- The feed rate of the material must be matched to the optimal speed of the end mill.
- A 50% reduction in operating speed can double the life span of your end mill.
- Choose the correct flute count for the application - proper chip evacuation is crucial as heated cutters can lead to low-quality cutting (burnt material, burred edging and dull tooling).
- Use carbide end mills for harder materials and high production applications.
- Sometimes extra length end mills are necessary to use, but to combat deflection (bending of the bit) operate at the proper speed and feed rates and always use the most rigid (shortest and widest) end mill available for the application.
- Use coolant or compressed air to prevent chip build-up.
- Use the whole side of the cutting edges rather than a small portion towards the tip. This will improve the shelf life of your endmill as the heat and work is distributed over a larger surface area.