Development of advanced power modules for electric vehicle applications

This paper discusses the manufacturing aspects for Insulated-Metal-Substrates (IMSs) with respect to high thermal conductive prepregs used and the Cu/prepreg/Cu stacks selected for each power application in the project. The IMS heat spreaders serve as high-current PCBs and heat dissipation routes for double side cooling of the Embedded power cores. The interconnection of the embedded power cores to the IMS high-current PCBs/heat spreaders is realised by silver sintering at the copper pads metallised by Ni/Au. The sintering technology is being developed and has yielded sinter deposits of 35-52ßm with single or double printing. Sintering takes place at a reduced pressure of 30 bar, which is actually the needed lamination pressure. The whole stack then is a power module with double side cooling. Furthermore, the paper will specifically highlight the first results on manufacturing of an "embedded" power discrete package as an example of an embedded power core having a 300ßm thin rectifier diode with 5μm copper metallisations on both sides, employing two distinct power diode embedded concepts with double side electroplated microvias.