IC packages are multi-layered structures with a large number of interfaces joining oxides, metals, and polymers. For these structures, interface separation is often the result of nucleation, growth, and coalescence of voids. The larger number of micro-pores and cavities observed within the adhesive film, as well as along the film–substrate interfaces, therefore poses a serious threat to the structural integrity of the IC packages. A common occurrence of interfacial failure is during the surface mounting of electronic packages onto the printed circuit board under reflow temperatures of 220–260°C. These temperatures exceed the glass transition temperatures, T g, of the polymeric adhesives and molding compounds and can induce high thermal misfit stresses at the die/adhesive and die/molding compound interfaces. Prior to reflow soldering, moisture diffuses through the hygroscopic polymeric materials and condenses within the micro-pores.