Evaluation of the Dielectric Cure Monitoring of Epoxy Molding Compound in Transfer Molding Process for Electronic Packages

The quality of molded electronic packages is strongly influenced by material characteristics of epoxy molding compound (EMC) and transfer molding process parameters. This work comprises the understanding of the effects of individual process parameters on the failure mechanisms and the evaluation of suitability of the online cure monitoring technique to observe the variations in material characteristic for transfer molding process. Molding temperature, preheat time, holding pressure as well as transfer speed are selected as process parameters. The effect of these process parameters on void formation and wire sweep is analyzed. Dielectric Analysis (DEA) is chosen as an in-situ technique and the suitability of the DEA is assessed for monitoring the cure behavior of the EMC regarding different variables. The effects of cure temperature, storage duration, moisture and material batch differences on the dielectric signal are studied and the variations on the ion viscosity and the cure behavior of EMC are discussed.