Abstract
Based on the advantages of finite element method,the variation of thermal strain and stress of the solder ball for Plastic Ball GridArray under specific thermal cycles has been studied. Due to the complicated geometries of the solder ball and surrounding components( for example, substrate, copper pad and PCB etc.), a highly efficientanalysis model which combines the merits of axisymmetric and 3-D elements is established. The effects of thermal cycling on the thermalfatigue life of the Sn63-Pb37 solder ball under elastic, elasto-plasticand elasto-plastic-creep analyses are then evaluated respectively. Bythe constructed formula for predicting the thermal fatigue life of the solder ball, the influence of solder ball shape ( sphere, cylinder andhourglass ) on the thermal fatigue life is also analyzed. The resultsshow that, under elasto-plastic-creep analysis, a cylindrical or an hourglass solder ball has longer fatigue life than a spherical solder ball.