Calibrated Fracture Process Zone Models for Polyimide/Metal Blisters

The objective of this work was to determine the adhesive fracture energies associated with various interfaces that were produced by different methods of applying polyimide to an aluminum substrate. Due to the relatively small thicknesses of the polyimide films, blister tests were considered most appropriate. Nonetheless, a considerable amount of global yielding was anticipated (Shirani and Liechti, 1994), even for peninsula blisters. In order to make sure that extracted adhesive fracture values were not masked by global yielding effects, a fracture process zone modeling approach (Needleman, 1990 and Tvergaard and Hutchinson, 1993) was taken.