Novel bonding and joining technology for power electronics - Enabler for improved lifetime, reliability, cost and power density

An increase in reliability and lifetime for power semiconductors at the same or lower cost and with the potential for higher power density remain high on the wish list for many Power Electronics Engineers. Power semiconductors continuously improve in current density year over year. However, without parallel enhancements in the thermal stack and the associated bonding and joining technology, significant limitations in harvesting these improvements remain. This is especially true when looking at the potential of SiC or GaN semiconductors where higher operating and switching temperatures are limited only by the available packaging technology. This paper presents a solution for a highly reliable power module concept. It is based on interconnect technology with outstanding reliability while maintaining the so desired design flexibility. For the presented solution, die attach is performed by a low pressure sintering process. The top side interconnects are achieved by using three innovative solutions: a sinterable top metallization, a metal buffer plate joined on top of the chip metallization (Danfoss Bond Buffer - DBB) and finally heavy Copper wire bonds.