Study on stacked AU bumps stress based on thermal-structure coupling

The 3D finite element analysis models of stacked AU bumps were developed, by using Isight software. The thermal-structure coupling analysis of the model was performed, the equivalent stress distribution of stacked AU bumps was obtained under the condition of thermal-structure coupling. The influence of the changes in stacked AU bumps structure on stress was studied. The influence significance of the below bump diameter, the below bump height, the above bump diameter, the above bump height on stress were obtained by variance analysis. The results of study show, the maximum stresses appear in the outer bump; With the increase of the bump height the highest stresses decrease gradually, with 99% confidence, the below bump diameter have highly significant impact on the stress, the below bump diameter, the above bump diameter, the below bump height, the above bump height affect the stress in a descending order.