Underfill Design Using FEM for FC-BGA, FC-CSP, and Moving Towards 2.5/3D

摘要

From Eutectic, to Lead Free, to Copper Pillar Bumping Technologies - as technology progresses to smaller process generations, new packaging applications are being demanded. Even so, low CTE epoxy materials are still needed in order to dissipate stress concentrations seen during thermal cycling. What epoxy challenges await this next technological revision? This paper will centralize around the latest advancements in epoxy materials for Advanced Packaging Technology and Capillary Underfill (CUF) for narrow pitch packages. Underfill materials must now be optimized for variable package designs to solve these failure modes. Optimized material properties must be quickly estimated using finite element methods in order to shorten the product development cycle. This paper will discuss solutions to typical failure modes currently seen in reliability testing of present and future technologies.