Temperature, moisture and mode-mixity effects on copper leadframe/EMC interfacial fracture toughness

A systematic investigation and characterization of the interfacial fracture toughness of the bi-material copper leadframe/epoxy molding compound is presented. Experiments and finite element simulations were used to investigate delamination and interfacial fracture toughness of the bi-material. Two dimensional simulations using virtual crack closure technique, virtual crack extension and J-integral proved to be computationally cheap and accurate to investigate and characterize the interfacial fracture toughness of bi-material structures. The effects of temperature, moisture diffusion and mode-mixity on the interfacial fracture toughness of the bi-material were considered. Testing temperature and moisture exposure significantly reduce the interfacial fracture toughness, and should be avoided if possible.