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

摘要

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 SO 2 causes general corrosion. Notably, the silver color changes significantly under SO 2 influence. EIS results show that the initial charge transfer resistance in the test containing SO 2 and Cl ? is 9.847 × 10 3 , while it is 3.701 × 10 4 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 HSO 3 ? concentration.