DBC substrate based EMC Transfer Molded Power Module

Abstract:
DBC substrate was used for a lead free solder SPM (Smart Power Module) made by transfer molding technology. Compared with general power modules made with leadframe insert injection moulded plastic housing, commonly used for motor drive applications, SPM has the advantages of quality, compactness, reliability and productivity by solving the process problems of joining the DBC substrate to the copper electrode leads, DBC ceramic cracking in transfer molding process and molding quality like EMC bleeding, package warp due to high EMC volume and package crack in application. This paper describes proposed package design, structure, its process flow, thermal resistance depending on ceramic materials like Al2O3 and AlN and package structures, reliability results of power cycle and thermal cycle lifetime and its failure analysis based on DBC based transfer molding structure comparing different kind of structures like gel filled power module. Package warpage data were included in addition to bolt torque evaluation results depending on package size and compared to bushing material insertion.