A process for extending the operating temperature limit of a polypropylene film capacitor to greater than 105° C., by use of a post assembly curing process of placing the capacitor in a 10 Torr or less pressure environment, preferably less than 1 Torr, and slowing heating it at a rate of less than an average rate of 5° C./hour to a peak temperature of about 10 to 20 degrees higher than the intended operating temperature, the peak temperature being not more than preferably 180° C.