Author: James S. Tonge Company: Dow Corning Corporation Date Published: 10/24/2010
Abstract: Portable electronic devices are now routinely used in increasingly harsh environments that include areas of volcanism and atmospheric pollution created by the burning of fossil fuels. This has increased the threat to devices containing silver and other metals from the corrosive effects of atmospheric sulfurous gases. This paper presents the results of several studies on the behavior of silicone coated Ag substrates exposed to sulfur based industrial pollutants including continuous corrosion rate monitoring of silver circuits on glass substrates. An accelerated exposure tool was used to derive the controlling parameters in circuit performance in a mixed gas atmosphere (H2S, NO2 and Cl2) at constant temperature and relative humidity. This work supplements previous studies on silicone protection of ferrous substrates and confirms that controlling the interface between the metal and the silicone is a key factor towards achieving long term Ag corrosion protection and reliability.