Understanding Mixed Flowing Gas Tests: Copper versus Silver

Mixed flowing gas (MFG) testing is used to demonstrate the ability of an electronic product or system to survive in a corrosive environment. MFG testing is designed to corrode copper and silver, which are often used as electrical conductors in electronic products. However, MFG tests have failed to identify issues in recent years. These failures have been predominately related to the corrosion of silver. To understand these test escapes, the corrosion of silver and copper corrosion under MFG is examined. For comparison, a flower of sulfur (FoS) test at 75°C was also conducted. The test results show that the rate of copper and silver corrosion is not equivalent but varies depending on the gas concentration, which explains the failure escapes.