Laser trimming of thyristors to add an overvoltage self-protected turn-on feature

Laser processing techniques have produced thyristors which are free from destructive overvoltage breakdown. Laser-fabricated structures that generate self-triggering currents are described. Test results demonstrate a temperature-stable switching voltage, uncompromised di/dt ratings, and the ability to withstand 14,000,000 successive overvoltage transients. Circuit implications of overvoltage self-protected thyristors are discussed.