| Abstract |
For high voltage modules, the demand on reliability is increased. For reasons of thermal conductivity
and thermal mismatch, Al2O3 ceramics have to be replaced by AlN. But thermal mismatch between
AlN and copper will reduce the reliability in state-of-the-art copper base plate systems. Therefore,
either better adapted materials (i.e. AlSiC) have to be used for base plates or a pressure contact system
without base plate must be designed. The analysis of the thermal mismatch and the thermal resistance
of pressure systems and AlSiC systems show, that the pressure contact system can be expected to be
the most reliable solution. A 3.3kV IGBT module in this technology contains 6 sub-units of 200A in
parallel, each connected with low inductance to a common DC bus bar. The integrated driver unit
supervises temperature and current. The CAL freewheeling diode has a high dynamical ruggedness.
The system is capable of a high power cycling reliability. |
