2.5 kV IGBT Module with High Reliability for Renewable Applications

Abstract:
The new 2.5 kV Si-IGBT module has been developed in the LV100 package for renewable applications. This module realizes high reliability, especially power cycling lifetime, by adopting the new structure “SLC+”. Available LV100 modules which represent our 7th generation modules achieved a high thermal cycle lifetime by the combination of Insulated Metal Substrate (IMS) and resin encapsulation, which technology was called Solid Cover “SLC”. In addition, the newly developed SLC+ structure have mainly two improvements. First item is enhancing the yield strength of bond wire. The newly developed Al-alloy wire is stiff to withstand mechanical stress which aids in robustness against bond wire cracking. Second item is to add hard metallization layer on the surface of chip for preventing the crack in the chip electrode. This function is useful for making full use of wire improvement. Experimental results would show the improvement of power cycling capability with SLC+ structure. On the other hand, the newly developed 2.5 kV IGBT and diode chip-set is optimized for 1500 V(dc) usage with consideration of trade-off between losses and LTDS robustness. The 2.5 kV chip-set consisted of 7th generation CSTBT(TM)-IGBTs and RFC-diodes enables power loss reduction and junction temperature reduction. That feature would show the validness for 1500 V(dc) or 900-1000 V(ac) operation with simple 2-Level topology. Besides, the suppressed Δ Tj swing also reduces the thermomechanical stress and contributes to lifetime improvement.