Thermo-mechanical finite element analysis in press-packed IGBT design

The reliability of press-packed insulated gate bipolar transistors (IGBTs) depends on satisfactory contact conditions applied at assembly stage and ma intained throughout the service life. The objective of this work is the sim ulation of stresses and strains in press-packed IGBTs due to assembly and t hermal cycling. Single-chip as well as multi-chip devices were analyzed wit h 2D and 3D models including an elastic-plastic material description and th e contact between components using the ABAQUS code. The assembly process wa s initially modeled and the factors affecting the contact pressure uniformi ty between contact disks and chip discussed. The thermal cycling associated with accelerated stress test was then introduced to examine contact pressu re evolution as well as local stress/strain concentrations and stick/slip c onditions. The device sensitivity to potential damage initiation due to the rmo-mechanical fatigue and/or fretting is addressed. (C) 2000 Elsevier Scie nce Ltd. All rights reserved.