– Sulfur-Resistant Film Resistors –

There are plenty of hostile environments that test the reliability of electronic components. Temperature extremes, dust, humidity and altitude are just a few conditions that designers have persevered against with rugged designs. Toxic chemicals and gases present some of the worst threats and are common conditions in many industries. In particular, high sulfur environments play havoc with everything from IT industry server farms and data/storage centers and telecommunication base stations to industrial control equipment and rubber, paper and oil manufacturing plants. For instance, sulfurous environments have a particularly negative impact on film resistors. Sulfur, when it reacts with elements such as silver, produces sulfide growth that can cause resistors to go open circuit.

Application of the sulfur-resistant resistor is no different than a standard film resistor when it is designed into systems and electronics applications.

In standard film resistors, their internal silver (Ag) or silver palladium (AgPd) terminal is only protected by the epoxy passivation layer making the device very susceptible to sulfur-based gases. These gases can attack the silver in the terminal starting the corrosion process based on surrounding conditions such as temperature, humidity and even air flow.

Realizing how sulfur gases can affect the reliability of its film resistors, Bourns developed a specialized Palladium (Pd) protection layer that covers the terminals removing the chance for corrosion and the formation of silver sulfide.

With the use of Bourns® sulfur-resistant film resistors, this corrosion-related type of hard failure can be eliminated, resulting in improved system reliability, performance, robustness and reduction of downtime.
This is one of the most important operating factors in the IT industry where subsystems such as memory modules are used heavily in server farms and the data/storage center marketplace. If your application needs to ensure critical data transfers even in unfavorable sulfurous environments, Bourns wants to help. Find out more in a Bourns white paper:  Advantages of Sulfur-resistant Film Resistors