Press Pack IGBTs modules have the characteristics of easy series connection and double side cooling widely used in industry, electric power, smart grid and other fields. Press Pack FRD (Fast Recovery Diode) chips is a component of Press Pack IGBTs module. In the actual operating conditions, the electrical parameters of FRD device will change in the electrical properties under pressure-stress, especially the Forward Voltage (VF) parameters. This change of the VF parameters will have adverse effect on the reliability of FRD chip and the overall module. In this paper, according to the stress of physical model of semiconductor material silicon were analyzed, proposed method to stress effect on the VF parameter of the FRD simulation analysis software.

The necessary condition for power devices with enough blocking properties is Junction termination technology. In this paper, starting with the dose of rings, 3.3 kV Floating Filed Rings was investigated, and the influence of electric field and current density on the breakdown characteristic is also described. The results show that the dose of field rings directly affects the stability of breakdown voltage, this impact is relevant to the location of the peak electric field and the peak current density when breakdown was occurred. When the peak electric field appears in the middle of the field rings, the breakdown voltage is not sensitive to the dose of rings; however, when the peak electric field and strongest current density appeared on the edge of termination at the same time, breakdown voltage become very sensitive to the dose of rings because of the highest impact ionization in this position. Simulations and experiments indicate that the junction termination has better withstand voltage stability , when electric field distributes uniformly, the position of breakdown is in the middle of the termination, and the strongest current density appears in the main junction.

In this paper, a new structure of Fast Recovery Diode (FRD) and its manufacture methods were investigated. The active region designed by TCAD simulation software could achieve low emitter injection efficiency, and then reduce the peak reverse recovery current, improve the reverse recovery softness and increase working stability. Meanwhile, the effect of the P-body dose and carrier lifetime on the turn-off characteristic of FRD was also discussed. Taking an example of 3300V voltage grade devices for FRD, the reasonable P-body dose and carrier lifetime on the basis of the new structure were confirmed by simulations. This diode was suitable for the anti-parallel with power switch device (such as IGBT, GTO, etc.).

This paper studied the relationship of breakdown voltage and charge imbalance of 600V tapered sidewall trench superjunction MOSFETs. Simulation structures including three types of structures: 600V vertical sidewall trench superjunction MOSFET (Type1) and 600V tapered sidewall trench superjunction MOSFET (Type2 and Type3). Under the condition of P-column and N-column uniform doping, Type1 structure has the highest peak breakdown voltage. Type2 structure has the lowest peak breakdown voltage under the condition of P-column doping concentration slightly lower than N-column doping concentration. The peak breakdown voltage of structure Type3 is higher than Type2, but the sensitivity of breakdown voltage in the charge imbalance state is the highest. The Gaussian dopant profile in P-column can make the peak breakdown voltage of the tapered sidewall trench superjunction MOSFET achieved the same level of the peak breakdown voltage of the vertical sidewall trench superjunction MOSFET. It is concluded that the sensitivity of breakdown voltage in the charge imbalance state is related to the structure: Type2 structure under the condition of P-column undercompensation and Type3 structure under the condition of P-column overcompensation are both beneficial to the process control.