Capacitors are indispensable to modern electronics. These passive components are comprised of multiple conductors separated by a dielectric material, which allows them to store a charge in the form of an electrostatic field. This enables rapid energy release—much quicker than is possible with an electrochemical storage device. The importance of capacitors, and indeed their ubiquity in modern electrical circuits, has given rise to a range of different capacitor types. Multilayer ceramic capacitors (MLCCs) and tantalum (Ta) capacitors are among the two leading systems used for premium electronics, but each of these technologies have critical engineering pain points. In this article, we will explore how fluoropolymer films can help alleviate some concerns in tantalum capacitor design, and give them a competitive edge over MLCCs.
To understand why fluoropolymer films have proven so successful in tantalum capacitor design, it is first worth recapping their basic working principles.
A solid chip tantalum capacitor is comprised of a sintered and oxidized tantalum anode enclosed in thin layers of manganese dioxide, carbon, and silver. The entire device is enclosed in a molded case with a tantalum wire protruding from the centre. Despite their exceptional performance properties, tantalum capacitors can succumb to MnO2 lifting if not properly insulated.
To combat the climb of MnO2 along the tantalum wire, a washer comprised of a fluoropolymer film like Teflon is used to prevent contact between the wire and the manganized layer.
MLCCs are designed differently, thus do not suffer from the issue of manganese solution climbing out from the wire. However, ceramic capacitors struggle to match tantalum-based devices on almost every front. They are useful for high frequency filtering and polarity orientation, but tantalum capacitors exceed their volumetric efficiency, reliability, DC bias capacitance stability, temperature stability, and more. Hence the interest in highly stable fluoropolymer films that can wrap tightly to wiring in tantalum capacitors and effectively eliminate the problem of MnO2 lifting.
At Saint-Gobain Films, we have developed an industry-leading solution for tantalum capacitor applications. CHEMFILM® SR LAM 001 is a composite fluoropolymer film designed for maximum durability and reliability in typical operating temperatures. With a tensile strength of 4500 PSI, an elongation value of 350%, and an operating temperature of 260C, our fluoropolymer film is an ideal alternative to skived film for tantalum wire washers in capacitor configurations. This enables optimal performance from tantalum capacitors, significantly reducing failure rates and enhancing user confidence. Interested in more information? Learn more about our fluoropolymer films products for further details or contact one of our experts today.