Thermal–mechanical optimization of a novel nanocomposite-film typed flip chip technology

The paper aims at optimization of the residual thermal–mechanical behaviors of a novel Flip Chip (FC) technology during and after the fabrication process. In this study, we first introduce the novel adhesive-typed FC packaging technology, consisting of a nanocomposite film for anisotropic electrical conduction and a nonconductive paste (NCP) for developing NCP joints. In the optimization work, the material and geometry properties and the bonding process parameters are considered as the design parameters, and the constraints on the residual behaviors and the design parameters are included. To deal with the multi-criteria design optimization problem, an effective metamodeling-based design optimization scheme is applied, which integrates parametric finite element (FE) analysis, a response surface methodology (RSM) and an updating scheme. Moreover, to assess the residual behaviors, a process-dependent simulation methodology that integrates both transient thermal and nonlinear contact FE analyses and a “death–birth” meshing scheme is carried out. The validity of the process-dependent FE simulation methodology is confirmed through experiment. Finally, two design practices are performed, and the calculated optimal designs are compared with each other and with the original design.It turns out that the present optimization methodology can be very effective and robust in seeking the optimal design of the FC technology with a better residual thermal–mechanical performance after the NCP bonding process.