A PROCEDURE FOR AUTOMATED SHAPE AND LIFE PREDICTION IN FLIP-CHIP AND BGA SOLDER JOINTS

In this paper, a three-dimensional shape prediction model and a finite element solution procedure for flip-chip and EGA solder joints are de veloped. The developed system is capable of calculating the solder joi nt geometry and the fatigue life automatically without any interventio n from the user The automation achieved will enable fast reliability e stimation and improved accuracy, since the two-dimensional finite elem ent mesh used for solder shape prediction is used to generate the thre e-dimensional finite element mesh for stress analysis. The implementat ion of the procedure is verified using the solution for-a flip-chip jo int from literature, and the capability of the code is demonstrated on a hypothetical three-dimensional solder joint with square pads that a re rotated with respect to each other, and offset from each other. The system developed in the study represents the first instance of an int egrated, automated finite element procedure for both shape and fatigue life prediction in general three-dimensional solder joints. The autom ation achieved in the system enables fast reliability estimation in a design environment and the optimal design of flip-chip and EGA solder joint configurations for maximum life.