Impact of Thermal, Moisture, and Mechanical Loading Conditions on Interfacial Fracture Toughness of Adhesively Bonded Joints

Interfacial delamination is a common failure mode in multilayered IC packages. In this paper, an experimental technique using Brazil-nut specimens is employed to determine the interfacial fracture toughness of an adhesively sandwiched joint with the introduction of edge interfacial crack. The design of experiments (DOE) is applied to study variations in strain rates and the thickness of the sandwich structure. In addition, the effects of moisture content and temperature on the interfacial adhesion are investigated. For the DOEs conducted, as the loading angle increases from 20° to 90°, the interfacial fracture toughness decreases. The fracture toughness and its corresponding mode mixity are determined from the measured critical load by finite element modeling computation.