Investigation of interfacial delamination of a copper-epoxy interface under monotonic and cyclic loading: experimental characterization

Interfacial delamination is of important concern for multilayered microelectronic packaging structures, as it is one of the most common failures observed in microelectronic packages. To predict interfacial delamination propagation under both static and cyclic loading, one needs to characterize interfacial properties. Key parameters for characterizing an interface include interfacial fracture toughness, interfacial fracture resistance, onset of delamination from an initial interface crack, and fatigue crack propagation (FCP) rate. The objective of this study is to experimentally investigate the interfacial properties of a copper-epoxy interface. Such an interface is one of the most common features seen in multilayered integrated substrates. Amenable to thin film process, sandwich double cantilever beam (DCB) specimens have been designed and fabricated in clean-room environment. Standard tensile tests have been preformed for determining the interfacial fracture toughness and, with monitoring the crack length against the applied force, interfacial fracture resistance. Fatigue tests have also been conducted in studying the onset of delamination from an interfacial delamination starter and the follow-up fatigue crack propagation (FCP) of an interfacial crack along the copper-epoxy interface.