Gas Recirculator for Debris Removal in Laser Etching Processes
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
The present apparatus greatly reduces debris build-up on optical windows in laser-assisted metal etching processes by flowing a recirculating mixture of a high pressure inert buffer gas with the etching gas over the window and into a filter to trap the debris. One of the major problems of laser-assisted chemical etching of metals is the glass window contamination caused by the reaction product deposition. In the etching process, a reactive gas, such as CP2, is used, and the pressure of the reactive gas is kept low to minimize the optical absorption of the laser beam by the gas. The reacted material, which is ablated by the laser, suffers few collisions with the gas molecules and therefore quickly deposits on the glass window surface.