Nonpunch-through IGBTs Research Articles

The Electrical Characteristics of High Voltage Non Punch Through (NPT) and Field Stop IGBT for Nano Convergence Power Devices

Power devices was used all of industry, widely because of switching devices. Specially, those devices could be applicable automotive and energy IT. This paper was proposed a 1500 V class NPT IGBT, in which a planar type was layered on the N-type wafer and the P-type collector was layered on the lower side. It also designed a field stop IGBT, which design process was similar to that of NPT IGBT but requires N+ to be inserted before layering the collector to create a buffer and layering the P-type collector. The electrical characteristics were derived after the design, and threshold voltage and on-state voltage drop, as well as breakdown voltage of the two devices were compared and analyzed. As a respect of threshold voltage, We obtained 4.21 and 4.11 V, respectively. And the breakdown characteristic of power devices is one of the most important electrical characteristics. The value of that was achieved 1818 and 1811 V, respectively. At last, we obtained 4.10 and 4.01 V of on state voltage drop, respectively. The comparison results showed that the field stop IGBT device constantly maintained an electric field at the drift layer due to the N+ buffer layer, indicating a small on-resistance while maintaining the breakdown voltage in the NPT device. Thus, it is expected to play a significant role as a switching device for high voltage over 1700 V in the future.

Investigation of the power dissipation during IGBT turn-off using a new physics-based IGBT compact model

New compact models of the IGBTs (both non-punch through IGBT (NPTIGBT) and punch-through IGBT (PTIGBT)) are presented in this paper. The models are implemented in the SABER circuit simulator and used for a study of IGBT anode current and voltage characteristics during a device turn-off (clamped inductive load circuit with gate controlled turn-off), since these parts of the transient characteristics essentially predict the power dissipation ( V× I) inside the device. It is shown that PTIGBTs are faster than NPTIGBTs, this becoming more apparent at higher clamp voltages.

2.5 kV-1000 A power pack IGBT (high power flat-packaged NPT type RC-IGBT)

A 2.5 kV-1000 A power pack IGBT (flat-packaged reverse conducting IGBT) has been developed using NPT (non-punchthrough) IGBT chip technology, the gate-source repair technology, the parallel connection technology with no oscillation and the multi-chip assembly technology. The power pack IGBT is specially designed for high power and highly reliable industrial and traction applications. Compared with conventional IGBT modules, this power pack IGBT has high reliability by use of a hermetic package and a press contact structure. In addition to the high reliability, this power pack IGBT is simple and compact for a 2.5 kV-1 kA class device because the assembled IGBT and FWD chips are able to shrink due to the low thermal impedance of both side cooling. The power pack IGBT shows the high blocking voltage of 2.5 kV, the typical saturation voltage of 4.2 V at the collector current (I/sub C/) of 1000 A, the junction temperature (T/sub i/) of 125/spl deg/C, and the turnoff capability of over 3/spl times/I/sub C/.

Electrothermal simulations in punchthrough and nonpunchthrough IGBT's

The performance of 1200 V punchthrough (PT) and nonpunchthrough (NPT) insulated gate bipolar transistors (IGBT's) is studied in detail under unclamped inductive switching (UIS) and short circuit (SC) conditions. The need for a good physics based simulator to carry out a reliability study is pointed out in the paper. Using such a finite element-based device and circuit simulator it is shown that NPT-IGBT's show a much better performance than PT-IGBTs under UIS condition. It is also shown that an NPT device has a better short circuit withstanding capability than a PT device due to the structural differences between the two devices. As there is a huge power loss within the device during these operating conditions, device self-heating is expected to have a significant impact on device characteristics. Electrothermal simulations are used to study device self-heating and it is shown that it significantly influences device performance under SC operation whereas self-heating influences the UIS performance of only the PT device with little effect on the NPT device. The study is validated by an experimental study of short circuit failure of PT IGBTs.

On the turn-off behaviour of the NPT-IGBT under clamped inductive loads

One-dimensional non stationary analytical models are presented describing the turn-off behaviour of the non-punch-through IGBT (NPT-IGBT) driven in a chopper circuit with a clamped inductive load. For this purpose the ambipolar device equations are solved by the integral method. Analytical expressions are derived for the carrier profiles in the n −-base during the extraction phase and the early tail phase. Analytical relations are also given for the time dependent anode voltage and the power losses in the extraction phase and the current decay during the early tail phase. Additionally, the ratio between the electron and the hole current at the p +-emitter during the early tail phase is investigated.

Power losses in PWM-VSI inverter using NPT or PT IGBT devices

This paper investigates the power losses for two different IGBT technologies (nonpunch through and punch through) for use in PWM-VSI inverters in order to choose the right device technology for a given application. A loss model of the inverter is developed based on experimental determination of the power losses. The loss model is used on two different modulation strategies which are a sine wave with a third harmonic added and a 60/spl deg/-PWM modulation where only two inverter legs are active at the same time. The two IGBT technologies are characterized on an advanced measurement system which is described. The total power losses in the inverter are estimated by simulation at different conditions and it is concluded that the nonpunch through (NPT) technology is most useful for higher switching frequencies, while the punch through (PT) technology is especially useful at lower switching frequencies and high load currents. It is also concluded that the 60/spl deg/-PWM modulation has the lowest power losses and the power losses are almost independent of phase angle cos(/spl phi/) for normal motor operation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A 2000 V non-punchthrough IGBT with high ruggedness

The inherently great ruggedness of a 2000 V non-punchthrough IGBT is demonstrated by operating the device under short-circuit conditions up to 1800 V and nearly 600 A cm −2. Even switching an inductive load without using a freewheeling diode at a current density of 350 A cm −2 is not destructive for the device. An explanation for the principally greater ruggedness of the non-punchthrough device (in comparison with the punchthrough IGBT) is given by a 1-D computer simulation, which leads to a fundamental understanding of the physics of the device.