Koh Yoshikawa

Ultra high-power 2.5 kV-1800 A power pack IGBT

The Power Pack IGBT has been tested in detail under several practical inverter systems and has obtained much useful data. Using this data and advanced technology, we have improved some items and finally developed an ultra high-power 2.5 kV-1800 A Power Pack IGBT (flat-packaged Reverse Conducting IGBT). One of the important improvements is the contact technology for the IGBT chip, and another is the electric discharge capability of the IGBT and diode chips. In addition to these important improvements, using our original 27.5/spl times/27.5mm/sup 2/ large IGBT and diode chips, and square flat package structure, we have achieved a compact and powerful device. The saturation voltage is 4.5 V at the collector current of 1800A and Tj=125/spl deg/C. The on-state voltage of the diode part is 3.5 V at the anode current of 1800 A and Tj=125/spl deg/C. The turn-off capability is over 4000A at the peak collector voltage of 2400 V. In this paper, the device structure, the chip technology, the parallel connection technology inside the package, the high blocking voltage capability, and other important experimental results are described.

Experimental investigations of 2.5 kV-100 A PT type and NPT type IGBTs

The electrical characteristics of 2.5 kV-100 A /spl mu/-stack IGBTs having Punch-Through (PT) and Non-Punch-Through (NPT) types of device structures have been experimentally investigated. By optimizing the p/sup +/ collector layer of the NPT type IGBT, the trade-off relationship between the saturation voltage and the turn-off energy can be obtained to fit on the curve of the PT type IGBT. The Reverse Biased Safe-Operating-Areas (RBSOAs) of the PT type and NPT type IGBTs fabricated are also very wide having a large turn-off capability of 800 A at the DC bath voltage of 1250 V.

4.5 kV-2000 A Power Pack IGBT (ultra high power flat-packaged PT type RC-IGBT)

A 4.5 kV-2000 A Power Pack IGBT (Flat-Packaged Reverse Conducting IGBT) has been developed by use of the PT (Punch-Through) type IGBT chip, the uniform chip parallel connection in the square ceramic package and the advanced multi-collector structure. The high turn off capability of 4500 A (@V/sub CC/=2600 V, T/sub j/=125/spl deg/C) and the short circuit capability of over 15 /spl mu/s (@V/sub CC/=3000 V, T/sub j/=125/spl deg/C) are successfully achieved.

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/.

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

A 2.5 kV-1000 A Power Pack IGBT has been successfully developed. This Power Pack IGBT is specially designed for the high power and highly reliable industrial and traction use. Compared with conventional IGBT modules, this Power Pack IGBT is simple and compact for a 2.5 kV-1 kA class device because the assembled IGBT and PWD 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 maximum on-state voltage of 4.5 V at the collector current I/sub c/=1000 A, T/sub j/=125/spl deg/C, and the turn-off capability of over 5/spl times/I/sub c/.

A study on wide RBSOA of 4.5 kV power pack IGBT

In this paper, high current turn-off capability of the 4.5 kV IGBTs is discussed. The dynamic avalanche phenomenon during a turn-off period limits the RBSOA (Reverse Bias Safety Operating Area) due to high impact ionization rate. It is demonstrated that the wide RBSOA can be realized with even a thin base layer. The newly-designed IGBT has successfully achieved the smaller turn-off dissipation loss and the sufficient RBSOA, simultaneously.

Short-circuit destruction of field-stop-structure inslated gate bipolar transistor

Numerical and experimental results of the field stop (FS) and lifetime control (LC) IGBT short-circuit characteristics using 4500 V-class devices are described. During the short-circuit condition, avalanche breakdown occurs along the base/FS layer interface. This is because the strength of the electric field becomes high due to the increase in the majority carrier concentration, which is larger than the impurity concentration in the base layer. The lower current gain in the device results in a higher electric field. It can be concluded that FS-IGBT has a narrower short circuit safety operating area (SCSOA) than other devices. Particularly, this phenomenon is easy to show on the high-voltage-class device, such as a 4.5 kV IGBT, because its impurity concentration in the base layer is low.

A novel IGBT chip design concept of high turn-off current capability and high short circuit capability for 2.5 kV power pack IGBT

A novel concept for achieving high electrical withstand capability on a high power IGBT is discussed in this paper. It should be noted that high turn-off capability of 6600 amperes (at peak collector voltage=2500 V, T/sub j/=125/spl deg/C) and the short circuit capability of over 50 /spl mu/s (at V/sub CC/=1600 V, T/sub j/=125/spl deg/C) are successfully attained by a newly developed power pack IGBT. In this paper, simulation results based upon the novel design concept are presented. Furthermore, experimental results are demonstrated to corroborate the simulation results.