The corrosion behavior of PCB-ImAg in industry polluted marine atmosphere environment

Publication date: 5 February 2017
Source:Materials & Design, Volume 115
Author(s): Lidan Yan, Kui Xiao, Pan Yi, Chaofang Dong, Junsheng Wu, Ziheng Bai, Chengliang Mao, Li Jiang, Xiaogang Li
This experiment was carried out in Wheat Island Qingdao which is characterized with a typical industrial polluted marine atmosphere environment. The atmosphere contains a large amount of Cl⁻ and SO2. The corrosion mechanism of printed circuit boards (PCBs) with an immersion silver surface finish (PCB-ImAg) in this phenomenon is still unknown. The corrosion behavior of PCB-ImAg is different under the influences of Cl⁻ and SO2. Silver has strong resistance to Cl⁻, which mainly causes micro-hole corrosion. However, silver is sensitive to SO2. The corrosion degree can be accelerated in the environment containing Cl⁻ and SO2. In this environment, the main corrosion products are oxides, sulfate and carbonate of silver and copper. The results summarized in this paper indicated that PCB-ImAg cannot be used in industrially polluted marine environment. Protective measures such as conformal coating are necessary to protect PCB-ImAg.

Graphical abstract

http://ift.tt/2fnZHj4