| Bios | 
| Presentation/Paper |
Robert Fleming,
Chuong Bui, Matthew Carlson, William Leonard
University of Central Florida
Subject Listing - Engineering
Advisor: Dr. Z. John Shen
Saturday, Oral Session 7, Presentation 3, Karpen Hall 006
MECHANICAL DEISGN OF A NOVEL HYBRID POWER MODULE
The purpose of this project was to redesign an IGBT power module based on the use of double metal leadframes, direct leadframe-to-chip bonding, size reduction, and injection-molded high temperature polymer encapsulation. Conventional power modules have complex material systems comprised of: multiple semiconductor chips, one or more ceramic substrates with metal interconnect films, a metal base plate, Al or Au wirebonds connecting the semiconductor chip to the substrate, soldered joints, epoxy casing, silicon-gel potting material, and external metal posts. This multifaceted material system joins dissimilar materials, which cause reliability issues at high temperatures or under thermal cycling conditions as well as increases material costs. The proposed design includes the elimination of wirebonds by using dual purpose copper plates that sandwich the chips and provide a flat surface for which the heat generated by the chips is dissipated effectively. This wire-free design will not encounter the parasitic impedance that is present from the use of metal wirebonds. The reduction in size will be accomplished both through the height loss from the plate-to-chip layout and from the epoxy encapsulation ring around the sides of the module that eliminates the need for bulky casings. This ring will eventually be injection molded as form an air-tight seal without any air pockets and will provide the flexural rigidity needed to withstand stress. The design has been accompanied by Finite Element Modeling and Thermal analysis for structural development. The thickness of the body surrounding the silicon chips including the epoxy was approximated to be 6mm with a copper plate thickness of 1mm. The manufacturing of the copper leadframes and the copper plates will be in the form of stamping in order to mass produce the components. With the decrease in size, reduction in impedance and selection of fewer materials demonstrate that this design could be highly sought for future applications.
Advisor: Dr. Z. John Shen, Associate Professor, Department of Electrical and Computer Engineering, University of Central Florida, Orlando, FL