Multilayer Strategy for Metallized Polypropylene Thin-Film Capacitors

Aktivitet: Foredrag og mundtlige bidragKonferenceoplæg


Metallized film capacitors (MFCs) are widely utilized in high power applications, due to their self-healing capability, high energy density and high reliability. Biaxially-oriented polypropylene (BOPP) is the most commonly used polymer in the capacitor industry but with a main limitation the 80 - 105°C maximum operating temperature. This trait of BOPP renders MFCs susceptible to failure in elevated temperature and voltage applications, as the lifetime degradation of such components is accelerated. Therefore, the thermal stability of MFCs in harsh conditions is of significant interest along with increase in volumetric efficiency.
In this work, a multilayer approach is proposed, employing two thin ceramic layers deposited on the BOPP foil, which improves the heat dissipation of MFCs. The samples are fabricated with the thinnest commercially available BOPP (1.9 μm thick), which undergoes a heat treatment prior to vacuum deposition of the ceramic layers as well as the metallisation. This process provides a cleaner PP surface, removes the wrinkles from the foil and aids in achieving better coating quality. Also, a special technique has been developed to stack a wrinkle-free multilayer MFC.
Atomic and Kelvin probe force microscopy investigations was carried to characterize the surface continuity of the different films. Tension experiments were also performed to evaluate the mechanical properties of the foil before and after evaporation. Heat dissipation tests were conducted to compare both the multilayer and conventional strategies under a thermal camera. Additionally, conventional microscope was used to define the capacitor device active area and assess the breakdown region. We obtained reproducible results regarding the capacitance, breakdown voltage, equivalent series resistance, and thermal responses exhibiting three times more efficient heat dissipation when a multilayer strategy is used.
Periode18. sep. 202321. sep. 2023
BegivenhedstitelThe 2023 Fall Meeting of the European Materials Research Society
PlaceringWarsaw, PolenVis på kort