Changes of loss factor of polypropylene film capacitors during long time thermal ageing

Abstract

Polypropylene film capacitors are high-quality electronic components used in many applications. PP capacitors are only available as leaded components, have a self-healing ability and low loss factor. The work was oriented on study of percentage changes of the loss factor of PP film capacitors during long-time thermal treatment at the temperature of 100 °C. The capacitance of measured samples was $\pmb{0.1\ \mu \mathrm{F}}$, class of the capacitors was X2. Products of five manufacturers were tested. Measurements were carried out using an RLC measuring device HP4284A. The percentage changes in the loss factor measured at the 1 kHz, 10 kHz, 100 kHz and 1 MHz frequencies due to thermal treatment for 20,000 hours were inspected. It was found that the changes are in the range of 1.4 to 3 % and that the changes only slightly depend on the value of the loss factor of the capacitors at the beginning of the test.