Heat Dissipation Derivation and Optimization of the Fan-Out 3-D Package Model

Heat dissipation of the fan-out (FO) package is a primary concern in advanced electronic packaging. It is a challenge to characterize the thermal performance using the actual geometry of the FO package due to the complex structure and time-consuming calculations. A simplified FO model was constructed based on the equivalent material principle and the mathematical FO model was validated by using the finite element (FE) simulation. Then FO-package thermal resistance network (FO-TRN) was established to evaluate the thermal performance, which was proven efficient and accurate by the simulation of FE models. The influence of the critical dimension (CD) of redistribution line (RDL), the thermal conductivity of molding material, and the printed circuit board (PCB) area were also investigated by using the FE simulation and FO-TRN calculation. The results demonstrated that the smaller the CD of RDLs, the greater the thermal resistance of the FO package. The high thermal conductivity of the molding compound and large PCB area is beneficial for heat dissipation. The simplified FO model and FO-TRN are practicable and effective for thermal characterization and management.