Comprehensive Investigation on Warpage Management of FOPLP with Multi Embedded Ring Designs

On the urgent multi-function requirements of mobile products and internet of things, a more than Moore's rule becomes a major concern in accordance with the scaling limitation of advanced devices. Accordingly, the architecture of fan out panel-level packaging (FOPLP) grows into the mainstream to meet the essentials of three-dimensional chip stacking and heterogeneous integration. Nevertheless, unfavorable warpage and residual stress issues resulted from the reconstruction and assembly processes of FOPLP are introduced, decreasing the assembly yield and subsequently long-term packaging reliability. To resolve the above-mentioned problem, this research proposes a 370 × 470 mm
²
carrier size FOPLP vehicle combined the novel designs of double embedded metal rings. The major geometrical characteristics of the foregoing metal rings are separately embedded in the multi-redistribution layers (RDLs) and epoxy molding compound (EMC) regions to control the process-induced warpage. On the basis of simulation-based factorial design, the key material selections, such as RDLs composed of photoimagable dielectric (PID) and EMC within the embedded metal rings, is investigated to significant restrain the induced warpage. Notably, a stiffer and a lower coefficient of thermal expansion (CTE) for PID are indicated to be an effective solution of miniaturizing the induced warp during the corresponding curing step. Consequently, a superior capability in warpage reduction after debonding process of panel level vehicles is acquired by means of the present simulation methodology and experimental validation.