Macro Meso Response and Stress Wave Propagation Characteristics of MCT High-Voltage Switch Under Shock load

Abstract

In order to study the dynamic and electrical coupling response characteristics of Metal Oxide Semiconductor Controlled Thyristor (MCT) high-voltage switch under the synergic action of mechanical load and high voltage, the separated Hopkinson pressure bar (SHPB) test system was used to simulate different impact load environments, and combined with the multi-layer high-voltage ceramic capacitor charging and discharging system, the instantaneous electrical signals of MCT high-voltage switch were collected. Combined with numerical simulation and theoretical analysis, the failure mode and stress wave propagation characteristics of MCT high voltage switch were determined. The mechanical and electrical coupling response characteristics and failure mechanism of MCT high voltage switch under dynamic load were revealed from macroscopic and microscopic levels. The results show that the damage modes of MCT high-voltage switches can be divided into non-functional damage, recoverable functional damage, non-recoverable damage and structural damage. Due to the gap between the metal gate and the oxide layer, the insulating oxide layer was charged. After placing for a period of time, the elastic deformation of the metal gate partially recovered and the accumulated charge disappeared, which induced the recoverable functional damage failure of the device. In addition, obvious cracks appeared on both sides of the monocrystalline silicon inside the MCT high-voltage switch, leading to unrecoverable damage of the device.

Keywords

• MCT
• Impact load
• Failure analysis
• Stress wave
• Numerical simulation