Corrosion inhibition performance of three imidazole derivatives in acidic etching solutions to fabricate copper lines of printed circuit boards

Corrosion inhibition performance of three imidazole derivatives, including 1,1′-sulfonyldiimidazole (SDI), 1,4-bis[(1H-imidazol-1-yl)methyl]benzene (BIMB), and 1,1′-carbonyldiimidazole (CDI), was investigated for copper corrosion in acidic etching solutions with 10 mmol L⁻¹ above corrosion inhibitors at 25 °C. Quantum chemical calculations and molecular dynamics simulations were performed to elucidate their adsorption behavior of the inhibitors on copper surfaces, and electrochemical measurements were used to evaluate their adsorption mechanisms. Furthermore, surface morphology characterization and etch factor analysis were conducted to assess the microstructural changes and etching efficiency of copper. Among the three inhibitors, CDI exhibited the best corrosion inhibition performance. Electrochemical testing results revealed that cathodic suppression dominated the corrosion inhibition of three inhibitors on copper: SDI and BIMB had the inhibition efficiency of <50%, whereas CDI had the highest charge transfer resistance for the inhibition efficiency of 72.01%. In the presence of CDI, the copper lines with line width/line spacing of 60 μm/60 μm and 30 μm/30 μm respectively achieved an etching factor of 16.55 and 13.24, outperforming BIMB and SDI. This work provides theoretical and experimental insights into the design of high-performance imidazole-based corrosion inhibitors for copper etching to fabricate copper lines of printed circuit boards.