Environmental Engineering Reference
In-Depth Information
century have yet to come true. Technologies always evolve, and new materials,
new processes and new ways of delivering a function ensure evolution. The ICE,
for example, is becoming a downsized copy of what it was, but performance is the
same, generally better, due to boosting. Boosted engines are facilitated by exhaust
driven turbochargers, electrically spun turbochargers, to hybridized engines. The
same is true for power electronics: the silicon power devices that have been with us
since the invention of the thyristor (SCR) in 1957 by GE continue to evolve to this
day. Consider the novel structure recently announced by ABB, Lenzburg, Swit-
zerland as the bimode insulated gate transistor (BIGT). This device with a con-
ventional IGBT section of each lithographic cell merged with a reverse conducting
(RC-IGBT) but with inter-digitated collector [5] exhibits 3.3 kV, 62.5 A, switching
performance in kHz range using lifetime controlled p-well (Figure 6.3).
E
Emitter
Gate
N
Fine pattern P
N
G
N
LpL
N
C
MOS cell
Emitter
MOS cells
RC-IGBT
IGBT
N
N
N
P
Collector
N
P
N
P
N
Figure 6.3 Silicon BIGT cell structure (courtesy ABB, Lenzburg, Switzerland)
With more integration at package level, the IPEM promises to push power
electronics to new heights and much broader scope of applications. As noted above,
and described in Reference 2, the IPEM is where the future is.
With power semiconductor devices today capable of much higher switching
frequencies, the parasitic's in the building blocks of Figure 6.4 will become func-
tional circuit elements in future highly integrated IPEMs. This, however, relies on
the availability of truly high frequency switching elements.
6.1.2 Wide bandgap devices
The world of power electronics is evolving more rapidly now as silicon carbide
(SiC), and most recently gallium arsenide (GaAs), power devices are growing
in capability. It was already mentioned that SiC in bipolar structure suited for
