Optimized Layout of 1700 V LoPak1 IGBT Power Module by Holistic Design Approach

Inhalt:
In this paper, a design method is presented, which takes into consideration various performance targets and combines the power of multiple simulation techniques to generate a holistic virtual prototype. With this method, multiple interactions are taken into consideration during the early stages of design, such as thermal behavior, resistive losses, static and dynamic current sharing between paralleled chips as well as electrical oscillations during short circuit operation, thus achieving a fast and accurate design prior to the construction and experimental realization of the modules during the design phase. The obtained simulation results of the virtual prototype are compared with experimental results of the 1700 V 450 A power module, which confirm the theoretical findings on the actual modules and demonstrate the power of virtual prototyping. This holistic design approach allowed us to combine the latest generation of ABB’s planar 1700 V SPT++ chipset for high-temperature operation of 175 °C and high Safe-Operating-Area (SOA) capability with a module featuring minimized self-inductance, low resistive losses, symmetrical high-and low-side switching. This allows our customers to fully utilize the switching capability of the IGBT with reduced cooling system requirements. A large number of design targets should be considered for a new power module such as: minimized resistive losses, minimized internal stray inductance, balanced coupling between the IGBTs, balanced current sharing in static and dynamic operation for the IGBTs and diodes and last but not least the impact on the junction temperature of the chip. Here, we demonstrate the predictive power of virtual prototyping to evaluate the impact of various design features on the electrical and thermal properties of the LoPak1 power module and highlight the outstanding properties in the experimental section.