Along the development of technology, the requirement of packaging with high I/O density and thin type has increased significantly. Accordingly, the fan-out panel-level packaging (FOPLP) becomes the mainstream to reach the essentials of three-dimensional integrated circuit. However, the warpage induced by the thermal stress during the manufacturing process is still an urgent issue. Therefore, finite element method is utilized to estimate the warpage of FOPLP in this study. The carrier size of proposed vehicle is 370 × 470 mm^2^. The novel designs of double metal rings are constructed to prevent the large warpage during the manufacturing process in the every single package. The double metal rings are embedded in the redistribution layers (RDL) and epoxy molding compound of FOPLP, separately. The fabrication process-oriented simulation flow is also considered to observer the formation in every step of manufacturing. The gravity effect is applied due to the large size FOPLP. On the other hands, the several equivalent methods are proposed to simplified the trace in RDL. The estimated warpage via equivalent methods are compared with experiment. The RDL is separated into two types of equivalent layers, pure photoimagable dielectric (PID) layer, and composite layer with PID and trace. The finite element simplified model of RDL is constructed to obtain the material properties of equivalent layers in RDL, Young’s modulus, shear modulus, Poisson’s ratio, and coefficient of thermal expansion. The simplified model of RDL considered the different copper content of every single composite layer in RDL. Moreover, the finite element model of FOPLP are divided into regions through the various of trace density in RDL to meet the deformation of real vehicle in the panel level package. The estimated warpage of FOPLP via finite element simulation is further verified with the warpage after experiment to confirm the methodology of equivalent material properties. To verify the equivalent method in the panel level package, the double metal ring is ignored while the validation between simulation and experiment. The simulation result in the panel level package with finite element approach equivalent method has the warpage 361.7 μm, which is the closest to experiment result 364.5 μm. The error between the warpage of the finite element simulation and experiment is 0.77% only, indicating that the equivalent methods is feasible. The various materials of PID are considered to improve the warpage of in the package level of FOPLP. According to the simulated results, the PID with lower curing temperature (170ºC) has the smallest warpage 27.83 μm. The curing temperature of PID greatly affect the warpage of FOPLP in this study. To further improved the warpage, the double metal rings are considered in the package level. The warpage can be declined to 12.72 μm. On the basis of results presented in this study, the equivalent method is successfully untiled and verified. The material selection of PID in RDL is also presented. Accordingly, the proposed novel designs of double metal rings improved the warpage of FOPLP.


Estimation of Suppressing Warpage for Heterogeneous Integration of Packaging Framework by Utilizing Equivalent Material Simulated Technique

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

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