Abstract CO2 laser drilling of blind hole is the necessary process to obtain high-density connection between different conductive layers for printed circuit board (PCB). A copper induced direct CO2 laser drilling blind hole was proposed to simplify the working process and enhance hole alignment with the aid of copper brown oxidation. Brown oxidized copper holding a roughened surface to extend the laser route in its surface and copper oxidation of CuO with a high laser absorptivity were investigated by scanning electron microscopy (SEM), 3D microscope, X-ray photoelectron spectroscopy (XPS), infrared thermal camera, and metallographic microscopy. It therefore breaks the limitation of pure copper stripped by CO2 laser. Example for CCL of top copper with thickness of 18 μm and dielectric resin with thickness of 80 μm realized the qualified Φ100 μm blind hole under 45 mL/L brown oxidation solution for 90 s.

中文翻译：

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铜诱导直接CO2激光钻孔盲孔棕色氧化PCB覆铜板

摘要 CO2激光盲孔钻孔是获得PCB不同导电层间高密度连接的必要工艺。提出了一种铜诱导直接CO2激光钻孔盲孔，以简化工作过程并借助铜棕色氧化增强孔对齐。通过扫描电子显微镜 (SEM)、3D 显微镜、X 射线光电子能谱 (XPS)、红外热像仪研究棕色氧化铜保持粗糙表面以延长其表面的激光路径和具有高激光吸收率的 CuO 的铜氧化和金相显微镜。从而打破了CO2激光剥离纯铜的局限性。