Fracture Mechanics Analysis of Low Cost Solder Bumped Flip Chip Assemblies With Imperfect Underfills

Solder joint reliability of flip chip on various thickness of printed circuit board with imperfect underfill is presented in this study. Emphasis is placed on the determination of the temperature-dependent stress and plastic strain at the corner solder joint with different crack (delamination) lengths. Also, the strain energy release rate and phase angle at the crack tip of the interface between the underfill and solder mask are obtained by fracture mechanics. [S1043-7398(00)01104-X]