Effect of Loading Mode, Temperature and Moisture on Interface Fracture Toughness of Silicon/Underfill/Silicon Sandwiched System

In this study, fracture tests of chip/underfill/chip sandwiched system were carried out, with non-contact and non-destructive digital image correlation (DIC) technique, under various loading angles from 20deg to 90deg different temperature levels of 25, 75 and 125degC or after moisture ageing at 85degRH, to study the effects of loading angle, temperature and moisture on the interface fracture toughness. With the results, the mode I and mode II critical fracture toughness based failure assessment diagrams (FADs) were established for reliability design and failure assessment of underfill/chip interface at different thermal cycling loading and moisture conditions