Molding Compound Effects on Warpage of Fan-out Wafer Level Packaging

Fan-out Wafer-level Packaging (FOWLP) technology has become one of the most rapid packaging technologies which can meet consumer demand for electronic devices. Since there are many advantages to FOWLP, several important issues remain to be addressed, including yield, reliability, thermal performance; die shift, and warpage. Therefore, the main reasons that cause the yield problem of the FOWLP are the mismatch of temperature loading and coefficient of thermal expansion(CTE) among the components of the package, and the other reason is the chemical shrinkage of liquid type epoxy molding compound during the cure process. In this study, the main goal is to assess the process-induced warpage of FOWLP during the fabrication process. To predict the amount of warpage precisely, a process-dependent simulation model which includes the cure-induced shrinkage of the liquid type of molding compound obtained by measurement, is proposed. To confirm the validity of the simulation model, the simulation results are compared to the online warpage measurement data. Finally, the influence of the material properties of molding compound parameters on the process-induced warpage is discussed.