Embedded power: a 3-D MCM integration technology for IPEM packaging application

Embedded power (EP) is the name for an integration technology for the power electronics switching stage, in which the multiple bare power chips, such as IGBTs, MOSFETs, and diodes, are buried in a ceramic frame and covered by a dielectric layer with via holes on the Al pads of the chips. Then, a planar metallization pattern is deposited onto it both for bonding to the power chips and a circuit wiring. The ceramic frame can be used as an extra thermal path and substrate for fabrication of the hybrid circuit with compatible thin- or thick-film techniques. When this integrated chips component is stacked with a base substrate and the associated components, a novel three-dimensional (3-D) multichip module (MCM) is produced. Such an integrated power electronics module (IPEM) offers performance improvement, functional integration, and process integration, as compared to conventional power hybrid modules. This paper presents the details of this technology, including the process design and implementation. A subsystem IPEM, incorporating power factor correction (PFC) and dc/dc switching stages for a distributed power system (DPS) front-end converter application, has been fabricated and characterized to demonstrate the feasibility of this power electronics integration technology. The capability for functional integration and the electrical performance improvement, which includes reduction in parasitics and increase in efficiency, are presented