(A) study on the material properties and process conditions of epoxy molding films (EMFs) for fan-out panel-level packages (FOPLPs)

Abstract

Recently, semiconductor packaging technology has become increasingly important due to demands for miniaturization and high performance of semiconductor products. Therefore, it is necessary to study the Fan-Out Wafer-Level Packages (FOWLPs) package method, which can realize high performance and miniaturization compared to conventional packages. As these FOWLPs are being studied, epoxy molding materials and passivation processes are becoming important. In addition, as the wafers become larger and panel size to reduce the package price, there are various problems in the current passivation method using the liquid type, granule or pellet type EMC such as materials non-uniformity and thickness control limitations. To overcome these limitations, new Epoxy Molding Films (EMFs) type materials and processes have been introduced to replace the current liquid, granule and pellet type EMCs. In this study, mixture of solid and liquid epoxies was used. After optimizing solid and liquid epoxies, the modulus, Tg, and CTE properties were significantly improved silica filler content up to 70 wt% used. In addition, the viscosity of the EMFs can be also decreased by the solvent content. The $10 cm \times 10$ cm size and the 400 $\mu m$ thick EMFs were prepared for molding. The molding processes of EMFs were performed at various temperatures using a hot press equipment. The voids inside the EMFs were investigated using the Scanning Acoustic Microscopy (SAM) equipment. Finally, thermal cycle (T/C) test and $85\circ C$ / 85% RH were performed to evaluate the effects of voids, delamination, and moisture of EMFs on Fan-Out Panel-Level Packages (FOPLPs) reliability.