摘要 |
By using a controlled arc-heated gas flow, material may be milled away from a substrate. By controlling the size of a gas flow aperture as well as other variables such as gas flow and arc current, small holes can be drilled into the substrate. Typically, these holes would have a diameter between 0.025 mm and 0.125 mm. In one embodiment, an arc made between an anode and cathode is placed above the work. A gas vortex is produced and is caused to pass through the arc, with the holes being drilled by the heated high-energy gas. Alternatively, the work may be used as the anode, with the gas flow carrying away material heated at the arc attachment point of the anode. The use of the arc-generated plasma gas vortex is particularly advantageous in the milling of multi-layer circuit boards.
|