Measurements of metal/polymer interfacial fracture energy in microelectronics packaging

Using the T peel test, the interfacial fracture energies of flexible Cu/Cr/ Polyimide films were deduced from the direct measurement of root curvatures and the elastoplastic beam analysis. The T peel strength and peel angle we re strongly affected by the Cu thickness and the biased rf plasma density o f the polyimide pretreatment. As expected, the interfacial fracture energy between Cr and polyimide increased with the rf plasma power density, but wa s pretty much independent of the Cu film thickness, implying it has a close relation with interfacial fracture toughness.