Micro-damage analysis in industrial alcohol-assisted nanosecond laser machining of ultra-thin copper foils

Ultra-thin copper foil, due to its excellent electrical conductivity and mechanical properties, has significant application value in advanced semiconductor packaging and the manufacturing of electrode materials for new energy batteries. Laser processing technology, with its numerous advantages, has become an important technical means for patterning the ultra-thin copper foil. However, the inherent material thermal accumulation effect of laser processing is prone to inducing material damage, severely restricting the processing quality and device performance. This study addresses the issue of damage suppression in ultra-thin copper foil laser processing, innovatively introducing industrial alcohol as an auxiliary processing medium, and deeply exploring the laser cutting mechanism and damage formation mechanism of ultra-thin copper foil in this medium environment. The research results show that the industrial alcohol-assisted medium plays multiple key roles in the laser processing process: first, it enhances the thermal diffusion efficiency and inhibits the expansion of the heat affected zone (HAZ); second, it provides a reducing atmosphere and inhibits the oxidation of molten copper; third, it changes the dynamic characteristics of the molten pool, optimizes the fluidity of the molten metal, and improves the cut seam quality. The synergistic effect of these physical and chemical effects significantly reduces the thermal damage of ultra-thin copper foil, while significantly improving the cutting efficiency and edge quality. By comparing with isopropanol alcohol (IPA), this further verifies the auxiliary advantages of industrial alcohol in the laser processing of ultra-thin copper foil. The research team has successfully developed an efficient and low-damage ultra-thin copper foil laser patterning cutting method based on the industrial alcohol-assisted medium. This method provides a simple and reliable technical solution for the preparation of high-quality ultra-thin copper foil microstructures, and has important theoretical and practical significance for promoting its application in high-end semiconductors, flexible electronics, and high-energy-density batteries.