Non-linear Viscoelastic Modeling of Epoxy Based Molding Compound for Large Deformations Encountered in Power Modules

Two experimental techniques (dynamic mechanical analyzer and fiber Bragg grating sensor) are used to characterize the viscoelastic properties of epoxy molding compounds. The creep and stress relaxation tests over a wide temperature range are conducted, and they are used to determine (1) the linear viscoelastic properties based on the thermo-rheological simplicity (master curve, Prony series and shift factor) and (2) the non-linear viscoelastic properties of one of Parallel Rheological Framework model (PRF) known as Bergstrom-Boyce (B-B) Model. The models are implemented for the EMC-based power module. The results obtained from the linear viscoelastic analysis and the non-linear viscoelastic analysis are compared, and the technical discussions including the limitation of the B-B model are followed.