Bhusari Rutuja, Bardon Julien, Guillot Jérôme, Philippe Adrian-Marie, Scholzen Sascha, Kaidi Zainhia, Addiego Frédéric
Structural Composites Unit, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg.
Advanced Analyses and Support Unit, Luxembourg Institute of Science and Technology, 5 Avenue des Hauts-Fourneaux, L-4362 Esch-sur-Alzette, Luxembourg.
Materials (Basel). 2025 Jul 14;18(14):3316. doi: 10.3390/ma18143316.
Double ultrathin copper foils (DTH), widely used for producing conductive tracks in electronics, consist of an ultrathin copper functional foil (FF), a nanometric release layer (RL), and an ultrathin copper carrier foil (CF). Achieving stable release strength of the CF during DTH lamination remains a key challenge, largely due to limited knowledge about the structure of the RL. In this study, a comprehensive characterization methodology is proposed to investigate the physico-chemical structure of a chromium-based RL, both before and after thermal exposure at 230 °C. Peel-off testing, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and transmission electron microscopy (TEM) were employed. The main structural transformation identified is the oxidation of the RL at the FF-RL interface, resulting in the formation of a chromium oxide layer. This transformation may underlie the significant increase in release strength, which rises from 5.9 N/m before thermal exposure to 163 N/m afterward.
双超薄铜箔（DTH）广泛用于电子领域中导电线路的制造，它由超薄铜功能箔（FF）、纳米级释放层（RL）和超薄铜载体箔（CF）组成。在DTH层压过程中实现CF的稳定释放强度仍然是一个关键挑战，这主要是因为对RL结构的了解有限。在本研究中，提出了一种综合表征方法来研究基于铬的RL在230°C热暴露前后的物理化学结构。采用了剥离测试、X射线光电子能谱（XPS）、原子力显微镜（AFM）和透射电子显微镜（TEM）。确定的主要结构转变是RL在FF-RL界面处的氧化，导致形成氧化铬层。这种转变可能是释放强度显著增加的原因，热暴露前释放强度为5.9 N/m，之后升至163 N/m。
