On The Mechanism of Nanosecond Laser Etching of a Metal Film Deposited on a Composite Material
J.P. Yang, N. Ren, G. Wu, R. Wang, L.X. Wang and K.W. Shang
Energy absorption and evolution in the etching process of metal films with pulsed laser have been analysed. An interfacial separation phenomenon between the metal films and the composite substrates under the irradiation of nanosecond pulsed fibre laser has been observed. This phenomenon is significant due to the easy vaporization character of composite materials. So, it is possible to significantly increase the etching precision of metal films by appropriately selecting the energy density of the laser pulse and without damaging the composite substrates. A demonstration experiment has been conducted using wavefront diffraction transformation technique, which verified the feasibility of this method.
Keywords: Fibre laser, nanosecond pulse, etching, metal film, aluminium (Al) film, Kevlar fibre, epoxy resin, interfacial separation, wavefront diffraction transformation