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.