Application of 1-hydroxybenzotriazole as a corrosion inhibitor in the super roughening of copper surfaces and its microscopic mechanism for significantly enhancing copper-resin adhesion strength

This study introduces 1-hydroxybenzotriazole (BTAOH) as a corrosion inhibitor in the surface roughening process of printed circuit board (PCB) manufacturing, which enhances the interfacial adhesion strength between copper substrates and epoxy resins. Copper-resin composites were prepared using the spray method and vacuum hot pressing. The enhancement of interfacial adhesion strength was evaluated through peel testing. Advanced characterization techniques, including scanning electron microscopy (SEM), atomic force microscopy (AFM), electron backscatter diffraction (EBSD), focused ion beam (FIB), and energy-dispersive spectroscopy (EDS), were used to elucidate the microstructural mechanisms underlying the improved adhesion. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were employed to validate the corrosion inhibition performance of BTAOH in acidic copper ion solutions and to discuss the mechanism by which BTAOH induces surface roughening of copper. Quantum chemical calculations further revealed the corrosion inhibition mechanism of BTAOH. Results demonstrated that the corrosion inhibitor significantly reduced the corrosion rate of the etching solution. The presence of BTAOH significantly enhanced interfacial adhesion strength between copper and resin by forming a selectively adsorbed surface structure that promotes adhesion. These findings suggest that BTAOH serves as an effective corrosion inhibitor during super-roughening processes while substantially improving copper-resin interfacial adhesion performance.