Electrical Properties of Thin Film Capacitors of Polymeric Alloys

Abstract

In this work, a parallel plate capacitor with insulating polymeric thin film from pure material of long chain Poly Metheyl Meth Acrylates (PMMA) and short chain of Poly Carbonates (PC) and Poly Methylene (PM) as well as of alloys (PMMA + PM). In order to get a good thickness, we used rotating technique. The current-voltage characteristic for these capacitor of a thickness (2000 oA) had been studied at room temperature. The breakdown voltage value were found for pure polymer of (PMMA), (PC) and (PM) equal to (1700 V), (2800 V) and (2000 V) respectively. But the breakdown voltage for alloys (75% PMMA + 25% PM), (50% PMMA + 50% PM), (25% PMMA + 75% PM), (75% PC + 25% PM), (50% PC + 50% PM), (25% PC + 75% PM) and (33.3% PMMA + 33.3% PC + 33.3% PM) are (2000 V), (1850 V), (1750 V), (2500 V), (1950 V), (1800 V) and (1500 V) respectively. The results have shown the behavior sequence breakdown in those capacitor. Finally, loading time for the thin capacitor which is consisted of (PMMA + PC), (PC + PM) and (PMMA + PC + PM) as a function of the numbers of breakdown has been studied, where it is found that the loading time increases with breakdown numbers increasing, and according to the results we have closed the best fabricated capacitor from (50% PMMA + 50% PM) alloy which we have found it to have a high loading time.