Large Area Powermodule Sintering Using Porous Copper

SiC power modules operate at 175°C and above. These high temperatures pose reliability problems for the soldered interface layer between the bulk copper of the AM B and the baseplate. As an alternative to soldering, sintering is being considered. In this study we present specially formulated higher porosity Cu sinter pastes for sintering 650 mm
²
substrates onto a Cu baseplate. One sintered interface connects the bulk copper of the baseplate to the bulk copper of the AM B, while the other connects the baseplate copper extended by a porous copper thick film to an AMB. Both samples were tested in thermal shock cycles (TSC) ranging from −30 °C to + 200 °C. The sintered interface, which connects the two bulk copper layers directly via the sintered copper layer, shows almost no delamination after 125 shock cycles. In contrast, the sintered bonding layer connecting the thick film copper to the AMB bulk copper fails completely.