Investigation of Cure Kinetics of Advanced Epoxy Molding Compound Using Dynamic Heating Scan: An Overlooked Second Reaction

Cure kinetics of epoxy molding compounds (EMCs) is a fundamental material property that affects the molding process of semiconductor chips and final package performance. However, due to measurement challenges related to the small polymer fraction, only the main reaction is considered in the current industry practice for EMC cure kinetics evaluation. In this work, we show that a second reaction exotherm is clearly identified in commercial multi-resin EMC systems upon dynamic heating scan using differential scanning calorimetry (DSC). The second reaction completes the overall reaction from about 0.8 to 1.0 fractional conversion, which is critical for designing cure schedules to achieve ultimate properties, especially the post-mold curing (PMC) procedure during manufacturing.