Temperature-Dependent Popcorning Analysis of Plastic Ball Grid Array Packaging During Solder Reflow with Fracture Mechanics Mothod

The popcorning effect of plastc ball grid array(PBGA)is analyzed using the method of fracture mechanics.The following specific problems are mainly studied:crack initiation in the die attach of the pack- age;crack growth in the die attach,and crack growth at the interface between the solder mask and coppr. Two different methods(crack tip opening displacement and virtual closure technique)are used to determine the crack-tip parameters such as the strain energy release rate,stress intensity factors,and phase angle for different crack lengths and temperatures.