TECHNICAL R Table 1 major Ratings and Characteristics Item Symbo Value epetitive peak off-state VDRM 8000V Average current 3600A di/dt ● ConventionaILTT On-state voltage Critical rate-of-rise of PLT(arbitrary units) off-state voltage ig. 3 The tradeoff between Pr and dv/ Minimum light triggering P 8.0mW power Turn-off time Thermal resistance 0.004°c tors. This arrangement has dramatically im- proved the turn-on characteristics: With an applied voltage of 8.8kV, a di/dt of 200A/us is achieved. Fig. 4 shows a typical turn-on wave- form at 8.8kV Units Lifetime control technology helps optimize the trade-off between VTm and Qrr, but conven- Time 1us/div tional techniques such as heavy metal diffusion and electron-beam irradiation affect the entire wafer. We chose instead to use proton irradia- Fig 4 The turn-on waveforms at 8.8kv. tion, which allowed us to control the lifetime profile in the thickness direction. This local- d lifetime control prevents a rise in VTM while reducing Qrr and the subsequent continuous o New LTT leakage currents. (There is no reduction of carrier ● ConventionalLY lifetime of the n-base. Fig 5 shows the trade- off relationship between VTM and Qrr of a con ventional LTT compared with that of this device indicating a 50% improvement. Table 1 lists the major specifications of the new device vement The unprecedented voltage and current ratings of this light-triggered thyristor will make it VrM(arbitrary units) possible to manufacture high-capacity power- control and power-conversion equipment that Fig. 5 The trade-off between VIM and Qrr is compact and reliable. O on the main thyristor more quickly, we devel oped a new dynamic gate structure in which the main thyristor area is dotted with pilot thyri 2. Mitsubishi Electric ADVaNceTECHNICAL REPORTS on the main thyristor more quickly, we devel￾oped a new dynamic gate structure in which the main thyristor area is dotted with pilot thyris￾Fig. 5 The trade-off between VTM and Qrr. Qrr (arbitrary units) VTM (arbitrary units) Key New LTT ● Conventional LTT 50% improvement 0.6 0.7 0.8 0.9 1.0 1.1 0.2 0.4 0.6 0.8 1.0 1.2 Light pulse Units VD 2,000V/div IT 250A/div Time 1µs/div IT VD Fig. 4 The turn-on waveforms at 8.8kV. Fig. 3 The tradeoff between PLT and dv/dt capability. PLT (arbitrary units) 70% improvement 0.01 0.1 1 Key New LTT ● Conventional LTT dv/dt capability (V/µs) 100 1,000 10,000 Table 1 Major Ratings and Characteristics Item Symbol Value Repetitive peak off-state VDRM 8,000V voltage Repetitive peak reverse VRRM 8,000V voltage Average current IT(AV) 3,600A Critical rate-of-rise of di/dt 200A/µs on-state current On-state voltage VTM 2.8V Critical rate-of-rise of dv/dt 2,300V/µs off-state voltage Minimum light triggering PLT 8.0mW power Turn-off time tq 400µs Thermal resistance Rth(j-f) 0.004°C/W Table 1 Major Ratings and Characteristics 32 · Mitsubishi Electric ADVANCE tors. This arrangement has dramatically im￾proved the turn-on characteristics: With an applied voltage of 8.8kV, a di/dt of 200A/µs is achieved. Fig. 4 shows a typical turn-on wave￾form at 8.8kV. Lifetime control technology helps optimize the trade-off between VTM and Qrr, but conven￾tional techniques such as heavy metal diffusion and electron-beam irradiation affect the entire wafer. We chose instead to use proton irradia￾tion, which allowed us to control the lifetime profile in the thickness direction. This local￾ized lifetime control prevents a rise in VTM while reducing Qrr and the subsequent continuous leakage currents. (There is no reduction of carrier lifetime of the n-base.) Fig. 5 shows the trade￾off relationship between VTM and Qrr of a con￾ventional LTT compared with that of this device, indicating a 50% improvement. Table 1 lists the major specifications of the new device. The unprecedented voltage and current ratings of this light-triggered thyristor will make it possible to manufacture high-capacity power￾control and power-conversion equipment that is compact and reliable. ❑