Accelerated Corrosion of Printed Circuit Boards due to High Levels of Reduced Sulfur Gasses in Industrial Environments

Accelerated corrosion leading to system failure has been observed on printed circuit boards present in industrial environments that contain abnormal levels of reduced sulfur gasses, such as hydrogen sulfide (H2S) and elemental sulfur. The problem is compounded by the fact that elemental sulfur is regulated by OSHA as a nuisance dust, and is allowed in a human working environment at the parts per thousand levels. Anecdotal data shows clearly that elemental sulfur gas present at the parts per million level can cause computer systems to fail within 2 months of use. Newer technologies such as immersion silver plating are especially susceptible to this type of corrosion. With the rapid growth of organically coated copper (OCC) and immersion silver platings, the number of failures due to reduced sulfur gasses in the environment has risen substantially