Abstract
Embedding active device technology is a very effective means of downsizing printed wiring boards, because of its large occupied area. Since a bare die is preferred in order to achieve a thin substrate, the flip chip mounting technique is inevitably used. In this case, resin is used to under-fill the gap between the bare die and the inner layer of substrate. In our evaluation using TEG chips, delamination at this part was found depending on the substrate structure, conductive pattern, and bare die size. Regarding these phenomena, thermal deformation analyses and actual deformation measurements were performed, and these results suggested the possibility of failure prediction even by elastic analysis. In addition, we found that thermal deformation could be reduced by adjusting the copper conductive pattern.
