Effect of solder volume on reliability in shape-designed CuCGA interconnect

In the CuCGA (Cu column grid array ) package, the failure occur first in the solder fillet at the solder/copper column interface and the crack propagates along the periphery of the copper column. So we have improved Cu column's shape by making the two bottoms of copper column into funnel-shape. Based on the reliability evaluation of interconnect, we established three-dimensional models of the double funnel-shaped CuCGA and analysed the influence of solder volume on strain distribution of double funnel-shaped CuCGA solder joint through finite element analysis software. The results indicate that, when the Cu column is made into double funnel-shape, the peak strain of solder fillers obvious decreases compared with that of conventional CuCGA. And the designed CuCGA interconnect has good comprehensive properties when the solder volume changes in a certain range. The reliability of structure can also be improved.