The popularity of insulated gate bipolar transistors (IGBTs) for use in high-voltage direct current (HVDC) transmission and flexible AC transmission systems (FACTS) is increasing. Unfortunately

for these applications wire-bond IGBT technology has a number of shortcomings

such as insufficient current ratings for the most powerful schemes

and inability to fail to short-circuit. Press-pack IGBT technology

conversely

offers increased current ratings

and an inherent short-circuit failure mode

making it a more attractive choice for HVDC and FACTS. However

the design and manufacture of these devices requires a comprehensive understanding of the unique technical challenges

which differ markedly from those for wirebond modules or traditional pressure contact devices. Specific challenges include providing a high degree of mechanical protection for the IGBT chip against normal operating stresses. Furthermore

it is essential to achieve uniform contact pressure across each chip surface to ensure optimum performance. To achieve this

manufacturers have designed products that use rigid copper electrodes manufactured to tighter tolerances than for other pressure contact devices

such as thyristors

and products that use compliant electrodes

incorporating spring assemblies. Dynex is in the advanced stages of development of press-pack IGBT technology with demonstrated robust solutions for the technical challenges outlined in this paper. Design success has been achieved through the use of state-of-the-art simulations in conjunction with a long history of manufacturing expertise for bipolar and IGBT products. Finally

multiple press-pack IGBT variants are currently undergoing evaluation tests prior to product release.