PRODUCTION ENGINEERING MEASURE. HIGH VOLTAGE SILICON RECTIFIER STACKS.
Quarterly progress rept. no. 14, 24 Sep-24 Dec 64,
INTERNATIONAL RECTIFIER CORP LOS ANGELES CALIF
Pagination or Media Count:
Serious difficulties were encountered in this quarter. Several tanks were found to have high values of leakage current when subjected to Group A hi-pot testing. In addition, two tanks arced internally due to either defective bushings or trapped air. New bushings were subjected to 200 of the voltage encountered in the hi-pot test and performed perfectly. A plexiglass cover was constructed to observe possible trapped air. It was determined that even with the most careful filling and vacuum treatment many air bubbles were trapped in the many crevices of the modules. In order to solve the problem of high dielectric leakage, modifications were made to the filling and process specification. These changes included more stringent drying procedures and vacuum techniques for removing air bubbles. A method of rocking the tanks was found to remove air bubbles trapped during the filling procedure. This method when checked with the plexi-glass cover proved to be very efficient and thorough. It is felt that the new procedure will solve the problems encountered during this quarter. Author