Film capacitor for high temperature applications
AssigneeDearborn Electronics, INC
InventorMark A. Carter
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Abstract
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.
Claims30
A monolithic polymer capacitor produced by the process comprising the steps of:
- vapor depositing at least two metal electrodes on polypropylene dielectric film;
- winding said film so as to insulate said metal electrodes from each other;
- applying a terminal connection to an exposed end of each said electrode thereby forming a capacitor;
- and
- curing said capacitor by steps comprising
- placing said capacitor in a low pressure environment, and
- gradually heating said capacitor to a peak temperature between about approximately 130° C. (403.15 K) and about approximately 200° C. (473.15 K) and maintaining said peak temperature for a period of time
- wherein said capacitor has a maximum operating temperature in excess of 120° C. for direct current voltages between 400 and 1200 Volts (V).
A method for producing a high temperature resistant metallized polypropylene capacitor, comprising the steps:
- depositing metal electrodes on polypropylene dielectric film;
- winding said film so as to insulate said metal electrodes from each other;
- applying terminal connections to an exposed end of each of said electrode thereby forming a capacitor;
- and
- curing said capacitor such that said capacitor has a maximum operating temperature in excess of 120° C. for direct current voltages between 400 and 1200 Volts (V), by steps comprising
- placing said capacitor in a low pressure environment, and
- gradually heating said capacitor to a peak temperature of at least about approximately 120° C. (393.15 K).
A method for extending the temperature range of a conventionally fabricated metallized polypropylene capacitor, comprising the step of:
- placing said capacitor in a low pressure environment of not more than 10 Torr, and
- gradually heating said capacitor to a peak temperature at least about approximately 10° C. higher than the desired operating temperature and greater than about approximately 120° C. (393.15 K).
A monolithic polymer capacitor, said capacitor comprising:
- a polypropylene dielectric film;
- first and second electrodes bonded to said film;
- and
- wherein said capacitor has a maximum operating temperature in excess of 125° C. for direct current voltages between 400 and 1200 Volts (V).
Dependencies are inferred from the claim text.