Pulsed laser-based material removal is a preferred micro-scribing technique for Copper (Cu) cladded onto an insulating substrate, such as a flame-retardant glass-reinforced epoxy resin (FR4), because of the less thermal diffusion as well as the process flexibility. This paper reports the pulsed laser-assisted micro-scribing of Cu (35 µm) from a dielectric material. The process was monitored by laser-induced breakdown spectroscopy technique (LIBS). For the complete removal of Cu from the substrate material, multiple laser scans were required. The Cu I line intensity in the LIBS spectra was decreasing with an increase in the microchannel depth. During the final laser scan, the FR4 substrate was getting ablated, and in the LIBS spectra, the characteristic emission lines from the substrate elements such as Calcium (Ca), Aluminum (Al), Sodium (Na) and Silicon (Si) were observed. The depth for a single laser pulse was estimated from a theoretical model, including the melt ejection due to the recoil pressure. Approximate microchannel depth was predicted based on the theoretical simulation.

基于脉冲激光的材料去除是一种首选的微划线技术，用于将铜 (Cu) 包覆到绝缘基板上，例如阻燃玻璃增强环氧树脂 (FR4)，因为热扩散较少且工艺灵活性。本文报告了从介电材料中对 Cu (35 µm) 进行脉冲激光辅助微划。该过程由激光诱导击穿光谱技术（LIBS）监测。为了从基板材料中完全去除铜，需要多次激光扫描。LIBS 光谱中的 Cu I 线强度随着微通道深度的增加而降低。在最后的激光扫描过程中，FR4 基板被烧蚀，在 LIBS 光谱中，来自基板元素（如钙 (Ca)、铝 (Al)、观察到钠（Na）和硅（Si）。单个激光脉冲的深度是根据理论模型估算的，包括由于反冲压力引起的熔体喷射。基于理论模拟预测近似微通道深度。