Delamination toughness of Cu-EMC interfaces at harsh environment

Interfacial delamination has become one of the key reliability issues in the microelectronic industry and therefore is getting more and more attention. The analysis of delamination of a laminate structure with a crack along the interface is central to the characterization of the interfacial toughness. Interfacial toughness is highly dependent to temperature, moisture and mode mixity. The present study deals with delamination toughness measurements of an epoxy molding compound - copper lead frame interface as directly obtained from a real production process in harsh environment, Temperature >;100°C & 100% RH. To deal with it, a chamber with high pressure, i.e. pressure vessel or pressure cooker, is needed. Controlling the inside pressure makes it possible to have 100% RH at different temperature levels. In addition to the initial stress state due to the harsh environment, mechanical loading under combined mode I/ II conditions is applied on a bi-material specimen to initiate and propagate the delamination. For this a mixed mode bending setup is installed in the pressure chamber.