Corrosion of contact surface on the printed circuit board both for thin Au plated (0.1µm) and for thick solder plated (10µm) were examined in SO2 environment. The corrosion was evaluated by contaminant film and contact resistance. The Au plated surface easily degraded. On the contrary, the film on the solder plated surface grew slowly. Acceptable low contact resistance was found.

Progress of corrosion of contact surfaces on the printed circuit board both for thin Au plated (0.1µm) and for thick solder plated (10µm) were examined in H2S environment. The corrosion was evaluated by thickness of contaminant film and contact resistance. The Au plated surface easily degraded by pore corrosion. On the other hand, the film on the solder plated surface grew very slowly. For the solder plated surface, acceptable low contact resistance which corresponds to the low growth rate of the film was found.