The effects of temperature and electric field on atmospheric corrosion behaviour of PCB-Cu under absorbed thin electrolyte layer

The effects of temperature and electric field on atmospheric corrosion behaviour of PCB-Cu under absorbed thin electrolyte layers were investigated by cathodic polarization and electrochemical impedance spectroscopy. Results indicate that the cathodic current density increases with increasing temperature, but decreases with increasing intensity of electric field. Electric field reduces the corrosion rate of PCB-Cu due to the aggressive ions migrating out from PCB-Cu electrode surface under the effect of electric field. When the ions can not freely migrate out from PCB-Cu electrode surface, local enrichment of aggressive ions under the electric field will cause serious localized corrosion of PCB-Cu.

Research highlights
► Design a setup for studying atmospheric corrosion by electrochemical methods.
► In situ study on atmospheric corrosion under adsorbed thin electrolyte layer.
► External electric field accelerates directed migration of Cl− ions.
► External electric field accelerates localized corrosion of copper film in fact.
► Temperature accelerates atmospheric corrosion of copper film.