Downsizing and footprint reduction are constant requirements of the market for all applications or equipment and the relative components. Film capacitors are not an exception and time by time is required to reduce the components dimension maintaining the same rated voltage and performances. Decreasing the volume of the components, one of the consequences is a reduction of the power dissipation by its surfaces and therefore a final increasing of its working temperature.
The paper was presented by Evangelista Boni, KEMET Electronics, Bologna, Italy at the 3rd PCNS 7-10th September 2021, Milano, Italy as paper No.4.1.
CONCLUSION
The new series have been developed to overachieve the Customers’ requirements anticipating the future market needs with a very high focus on the temperature performances. Only few years ago, it was considered not possible and safe to have series in Polypropylene dielectric film working continuously at 125°C. It’s well known the decreasing of the IR and the exponential increasing of the shrinkage of such film at temperature above 105°C. During these years KEMET Advanced R&D Department worked deeply on the root causes analysis for the failures observed during test performed at high temperature. This activity allowed to determine the real weight of each cause related to process and materials and therefore working in an effective way for the improvement of the new series.
With such new series KEMET has merged the requirement to increase the working temperature with general new trend as:
- Withstanding the THB requirement at 85°C/85%RH with Vr applied
- Increasing the dV/dt withstanding as required by the implementing of the new SiC & GaN technology
Moreover, the launching of the new C4AK products made with the new HTDF (High Temperature Dielectric Film) represents a first step of new generation of series able to work in the new advanced applications.
REFERENCES
[1] C4AK Application Note, KEMET
[2] M Michelazzi，E Boni，D Montanari, “RFI X2 capacitors for high humidity environment”, CARTS International, 2014
[3] Luca Caliari, Paola Bettacchi, Evangelista Boni, Davide Montanari, Arrigo Gamberini, Luigi Barbieri, Francesco Bergamaschi, “KEMET film capacitors for high temperature, high voltage and high current”, CARTS International, 2013
[4] J.H. Tortai, A. Denat, N. Bonifaci, “Self-healing of capacitors with metallized film technology: experimental observations and theoretical model”, J. Electrost., vol.53, pp.159–169, August 2001
[5] H. Li, P. Lewin, J. C. Fothergill. “Aging mechanisms of X2 metallized film capacitors in a high temperature and humidity environment.” IEEE International Conference on Dielectrics, pp.804-807, July 2016
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