Is the temperature of the NTC thermistor in an IGBT module the same as the case temperature Tc?

The temperature of the NTC thermistor and the case temperature are different. Generally speaking, the case temperature Tc directly under the chip becomes higher than the temperature of the NTC thermistor.

Can we consider that the case side temperature of an IGBT module is the same as the case temperature Tc?

The case side temperature and the case temperature Tc are different. Heat of a semiconductor chip is conducted through an insulating substrate to the copper base and heatsink. The case side temperature becomes considerably low, compared with Tc.

Can we consider that the case temperature Tc is an average value across the copper base plate?

It is not an average value across the copper base plate. It is the case temperature directly under the chip.

Can we assume that the case surface temperature and the case backside temperature of a discrete IGBT the same?

There is a temperature difference between the surface temperature and the backside temperature. The latter becomes higher.

When we apply VGE=15V, is it OK to consider the only range of 15V for SCSOA?

As short-circuit current is determined by the gate voltage, the SCSOA has to be judged by the gate voltage at the time of a short circuit. As the gate voltage may go up in some cases at the time of short circuit, investigation under the worst conditions is recommended.

When using an IGBT gate driver IC, do you have any recommended circuits for overcurrent protection?

Follow the recommended circuit for the driver IC. Detemine the circuit constants so that the protection operation will be finished within the period of the short-circuit time indicated for each series.

After soldering of small IPM products, is it ok to cut their pins off?

There no problem in cutting pins. But please be careful not to apply stress to the PCB.

What are the differences between a 2-level inverter and a 3-level inverter?

A 3-Level inverter realizes system miniaturization and higher efficiency compared to a 2-level inverter. A 2-Level inverter controls the voltage waveform of the converter output with 2 electric potentials while a 3-level inverter controls it with 3 electric potentials. As the 3-level converter creates an output waveform closer to a sinusoidal curve, a reduction of […]

An IGBT module is broken. How can we investigate the cause?

The breakdown mode of an element may include overcurrent, overvoltage, overheat, etc. Causes of each breakdown mode have to be investigated. In the real world, however, it is difficult to identify the cause by the breakdown status of an IGBT module alone. It is important to consolidate information such as the breakdown voltage VCE, current […]

Do all switching losses depend on the gate reverse-bias voltage between the gate and the emitter (-VGE)?

Mainly the turn-off loss Eoff will be affected. As –VGE increases, Eoff decreases.