There is rapidly growing demand for film capacitors for use in high-temperature, high-power applications such as electric vehicles, electric aviation, power electronics, and aerospace.
The lack of reliable high-temperature, high value capacitors has almost certainly limited growth in these newer applications. Most current capacitor technologies on the market, such as aluminium electrolytics or film capacitors, are limited to a maximum temperature range of 125oC - 150oC or even lower.
What is the maximum temperature a capacitor can withstand?
Most current capacitor technologies on the market, such as aluminium electrolytics or film capacitors, are limited to a maximum temperature range of 125oC - 150oC or even lower. To achieve higher temperature ratings, ceramics and tantalum capacitors are used. In downhole electronics, high temperature is usually classified as 150oC and above.
What type of capacitor is used in high temperature applications?
The supply of high-temperature ceramic capacitors for applications above 175 C is highly fragmented, with many of the smaller, more specialized vendors of ceramic capacitors offering a variation on the high temperature ceramic capacitor. Tantalum – Certain types of tantalum capacitor designs are used in high temperature applications.
What is a high-temperature capacitor?
High-temperature designs incorporate metals such as tin, palladium-silver and gold plating which have melting points well above the temperature rating of the capacitor. These materials perform well at elevated temperatures and should be considered a critical part of the construction in such a demanding environment.
Capacitor manufacturers are also exploring new high temperature dielectrics, especially in “self-healing” plastic film, which is preferred in mission critical circuit applications. Emerging capacitor dielectrics operating at these temperatures include silicon, solid aluminum and aluminum oxynitride type capacitors.
To summarize: There is increased market activity in the 175 degree C to 450 degree C capacitor markets because of the commercialization of space and the impact geothermal electronics. Established dielectrics operating at such high temperatures include ceramic, tantalum, plastic film, glass and diamond-like capacitors.