XPS investigation on Upilex-S polyimide ablated by pulse TEA CO2 laser |
| |
Authors: | D W Zeng K C Yung |
| |
Institution: | Department of Manufacturing Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, PR China |
| |
Abstract: | Laser ablation of Upilex-S polyimide films 80 μm thick was performed in air using a pulse TEA CO2 laser with wavelength 9.3 μm. A halo surrounding the hole was observed, which is covered with sub-micro particles. Pieces of ablation products protrude from the ablated surface, leading to considerable roughness of the ablated area. Chemical and structural changes of Upilex-S polyimide film surface irradiated by the pulse TEA CO2 laser in air were analyzed by X-ray photoelectron spectroscopy (XPS). Relative C content in the ablated area was found to be higher, whilst both O and N contents were lower than in the untreated area. This means that TEA CO2 laser ablation released both the O and N atoms. Also, the peak areas corresponding with carbonyl group (C=O) in the imide system were reduced much more and a new component at 287.0 eV assigned to the amide structure (N---C=O) was detected after laser ablation. These suggest that the pyrolysis of the Upilex-S polyimide was the decomposition of the imide ring between the nitrogen/aromatic carbon atom and carbonyl carbon atom. In addition, another new component arising from >C=O groups was also detected for higher fluence (7.83 J/cm2), and its peak areas is very small. This result indicates that the slight oxidation may take place with higher fluence during laser ablation in air. Based on above-mentioned experimental results, a possible thermally-induced decomposition path of Upilex-S polyimide ablated by TEA CO2 laser is presented. |
| |
Keywords: | Pulse TEA CO2 laser ablation Upilex-S polyimide X-ray photoelectron spectroscopy (XPS) |
本文献已被 ScienceDirect 等数据库收录! |
|