Switching time control on power high voltage bipolar transistors for high definition VDT by electron irradiation

Transistors used as switches in horizontal deflection circuits for high definition TV and Video Display Terminals were subjected to electron irradiation using a 12 MeV linear accelerator. The use of electron irradiation has made possible a fine control of the charge carrier lifetime thus improving the switching time and greatly reducing the power losses at turn-on and turn-off. Devices able to work at horizontal deflection frequency from 32 kHz up to 64 kHz, 1.2-1.5 kV and to handle current between 2 and 10A have been obtained. The effects of the thermal processes, that the irradiated devices undergo during assembly and packaging operations, have been investigated. (author)