Yageo has recently released its new "anti-sulfurated resistors" AF series. These resistors are suitable for use in environments exposed to high level of sulfur contamination like industrial control systems, sensors, electric instrumentation, and communication base stations, etc. It is also suitable for areas with high concentration of sulfur such as hot springs and mines.
According to Yageo the AF series satisfy the most demanding product applications with a high degree of reliability. Mass production of the AF series began this year and it is already approved and used by major telecommunication equipment makers in Japan and Taiwan. Yageo offers AF series resistors in full size range, 0402/0603/0805/1206, with high degree of anti-sulfurated capabilities. According to international norms ASTM test, Yageo's AF series meets the most stringent testing standards with excellent anti-sulfuration characteristics.
In general, sulfur penetrates into resistor through the gap between the termination and the protective layer, thus producing silver sulfide compounds with the silver used in the electrode. This renders the entire resistor into an insulator thus achieving anti-sulfuration capability.
Yageo officials stated "as environmental pollution is a rising concern, there has been an increasing demand by terminal equipment manufacturers for anti-sulfuration features in the past two years. Yageo received a steady stream of customer inquiries, which led to more focus on anti-sulfurated resistor research and development. We were thus able to get the AF series up and ready before local competitors, providing our customers with alternative choices to Japanese manufacturers. We anticipate that customers using the AF series resistor will see even more optimal product performance and dependability that coincides with their demand for better end product design applications." In contrast to industrial electric instrumentation and base station equipment, most consumer electronic products don't have anti-sulfuration requirements. However, certain atmospheric conditions release substances causing sulfuration reaction which further affects the efficiency of electronic products. This makes it necessary for some electronic product manufacturers to use anti-sulfate resistors under extreme environmental condition.