Pulsed CO2 laser etching of polyimide

Abstract

Etching of thin polyimide films in air was investigated using a line tunable, pulsed CO2 laser. The threshold fluence for etching at a wavelength of 944 cm−1 (10.6 μm) exceeds that at 1087 cm−1 (9.2 μm) by a factor of 4. This is consistent with the infrared absorption spectrum which shows polyimide to be significantly more absorbing at 1087 cm−1. As a result, etching at 1087 cm−1 produces a cleaner, more precisely defined region. Analysis of the vapors generated during laser etching shows the simple gases CO2, H2O, and CO to be present.

Excimer laser polymer ablation: the first 20 years

“…In this picture bond breaking will occur principally from the ground electronic state of the molecule. That a purely thermal process can produce effective polymer ablation has been confirmed by a number of investigations using long wavelength pulsed CO 2 lasers, where the photons coupled to vibrational modes of the molecule [14,15]. The general findings (threshold behaviour, dependence on absorption coefficient) mirror quite closely those for excimer lasers when account is taken of the generally lower absorption coefficients for vibrational transitions.…”

Laser induced surface modification of clay-PAN composite nanofibers

“…In this work CO 2 pulsed laser is applied for surface modification of nanofibers, due to its wave length, larger beam size, larger pulse energy, higher laser efficiency and by using non toxic gases [19]. A Gaussian laser beam was focused to a spot of 170 mm diameter to get selected laser power densities.…”

Decolourization of vat dyes on cotton fabric with infrared laser light

“…IR lasers provide a wider field of application due to cheaper light sources working with higher energy output and no use of toxic gases. CO 2 lasers, which produce light with a wavelength of 10.6 lm, are used for creation of the worn look of denim fabrics in the textile industry as an alternative method to conventional techniques for the fading process (Brannon and Lankard 1986). Decolourization with CO 2 lasers is applied to denim fabric to create a worn look (Ö ndogan et al 2005;Dascalu et al 2000;Ö zguney et al 2009).…”