Corrosion Behavior of Silver-Plated Circuit Boards in a Simulated Marine Environment with Industrial Pollution

The electrochemical corrosion behavior of a silver-plated circuit board (PCB-ImAg) in a polluted marine atmosphere environment (Qingdao in China) is studied through a simulated experiment. The morphologies of PCB-ImAg show some micropores on the surface that act as the corrosion-active points in the tests. Cl^- mainly induces microporous corrosion, whereas SO₂ causes general corrosion. Notably, the silver color changes significantly under SO₂ influence. EIS results show that the initial charge transfer resistance in the test containing SO₂ and Cl^- is 9.847 × 10³, while it is 3.701 × 10⁴ in the test containing Cl^- only, which demonstrates that corrosion accelerates in a mixed atmosphere. Polarization curves further show that corrosion potential is lower in mixed solutions (between -0.397 V SCE and -0.214 V SCE) than it in the solution containing Cl^- only (-0.168 V SCE), indicating that corrosion tendency increases with increased HSO₃^- concentration.