Laser ablation behavior and mechanism of polyimide by UV irradiation

ABSTRACT

A research focused on ablation characteristics of polyimide (PI) film induced by a nanosecond ultraviolet (UV) laser was presented. The effect of varying the laser power (P), scanning speed (S) and their combined impact – linear laser energy density (LLED) on the ablation behavior on PI was investigated. The characteristics of both photothermal and photochemical ablation regimes were observed, which extremely depend on LLED. A relatively narrow interference ablation region (~43 μm) was observed at low LLED (< 3 J/m) and a typical photothermal ablation area (~101 μm) was observed at high LLED (> 6 J/m) accompanied with thermal expansion and cracks. The surface morphology and composition was analyzed using SEM, EDX, and Raman spectroscopy. Then through TGA-FTIR and Py-GC–MS technique, the composition of the residue and the decomposition process were discussed in detail. The experimental results and developed mechanism offer some insights into the characteristics of UV laser ablation of PI film.

KEYWORDS:

• Laser
• ablation
• polyimide
• UV
• photothermal
• photochemical
• decomposition
• mechanism

Acknowledgments

The general characterization facilities are provided by the Flexible Electronics Manufacturing Laboratory in Experiment Center for Advanced Manufacturing and Technology in School of Mechanical Science &Engineering of HUST.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [52005206, 51905191], the China Postdoctoral Science Foundation [2020TQ0110], Ministry of Industry and Information Technology’s special project for high-quality development of manufacturing industry Ministry of Industry and Information Technology’s special project for high-quality development of manufacturing industry [TC200H02H], National Key R&D Program of China [Grant No. 2020YFB2007600], Scientific Research Plan Guiding Project of Hubei Province Education Department [B2019246], Key Research & Development Plan of Hubei Province [2020BAB051], Guangdong Provincial Key Laboratory of Digital Manufacturing Equipment [2020B1212060014], Guangdong Basic and Applied Basic Research Foundation [2020A1515011393].