Interface Fracture Toughness Characterization in Electronic Packages Using the Crack Surface Displacement Extrapolation Method

The present paper deals with the fracture toughness characterization of the interface formed by an epoxy-based molding compound and a printed circuit board (PCB) substrate. Both experimental and numerical analysis are performed. Specimens are investigated by delamination experiments under mixed-mode loading conditions at room temperature. Obtained interface toughness is interpreted via finite element modeling using Crack Surface Displacement Extrapolation Method (CSDEM). We found that the weakest interface in the analyzed sample is the one comprised of the copper trace and the solder mask, i.e. failure by delamination occur inside the printed circuit board, and not at the interface molding compound/solder mask.