IGBT Modules - Technologies, Driver and Application (Second Edition) - page 57

Reduced switching losseswhen turningon and off
Soft switchingbehaviour
Increased current density per sectional unit
Increased voltage rating
Reduced use of semiconductor material (i.e. reduced surface and gauge while
retaining voltage and current values), with consequent reduction in cost
Increasedmaximum operational junction temperature
Expanded SOA (safe operating area), particularly the RBSOA (reverse biased
safe operating area) and SCSOA (short circuit safe operating area). One
specific development goal for expanding the SOA is known as the switching
self-clamping mode (SSCM), the idea being to use the SSCM to extend the
SOA for high-voltage IGBTs. A power surge that is beyond an IGBT's
breakdown voltage can destroy the IGBT if it occurs when the IGBT is being
turned off. In an SSCM IGBT, the IGBT itself limits the power surge to a value
below the breakdown voltage. The IGBT goes into what is known as a
dynamic avalanche (chapter
IGBTmanufacturers are taking a variety of approaches, most of which are targeting the
same thing: Continually improving the cost-performance ratio of the IGBT to obtain an
ideal switch and/or further increase the performance specifications. The usual way to
present and compare different IGBT developments is in a trade-off diagram, which
compares the forward voltages U
and switching losses (combined turn-on and turn-
off losses). The ideal switch in this diagram should be at U
= 0V and E = 0mJ. As
can be clearly seen in
the switches are improving all the time, even if
perfectionwill never be achieved.
Fig. 1.35
Examples of development stages of IGBT semiconductors
1...,47,48,49,50,51,52,53,54,55,56 58,59,60,61,62,63,64,65,66,67,...548
Powered by FlippingBook