Fully cure-dependent polymer modeling and application to QFN-packages warpage

Process-induced warpage is an important issue for package reliability. In order to model the warpage generated during the molding process of QFN packages, a full experimental material characterization of model molding compounds is discussed in This work. Through a method of intermittent cure experiment, the master curve and both a "temperature shift factor" and a "conversion shift factor" are obtained. A series of molding experiments for QFN matrix strips with the model-molding compounds were performed. In the molding process, different combinations of molding temperature/time and post-cure/time were used. The warpage after molding and after post-cure was measured, respectively. The results show that both the filler percentage and the die thickness have significant effects on the warpage level.