Thermal Curing Kinetics and Adhesion Strength of a Novel Photosensitive Dielectric Build-Up Film for Advanced Packaging Substrates

The limited interfacial adhesion of photosensitive dielectric materials poses a critical challenge to the reliability of advanced packaging substrates, particularly for ultra-fine line fabrication. However, their curing behavior is complex and poorly understood, hindering effective control of interfacial adhesion. Herein, the thermal curing behavior of a commercial photosensitive dielectric build-up film (PVF) after photo curing was analyzed using non-isothermal differential scanning calorimetry (DSC) based on nth-order and autocatalytic models, and the adhesion strength between copper and PVF was evaluated by tuning the curing behavior. DSC results show that PVF exhibits two overlapping exothermic peaks, and both reactions follow autocatalytic kinetics. A quantitative correlation between curing behavior and interfacial adhesion was established. The Cu–PVF adhesion strength initially increased and then decreased as the curing time extends from 60 to 100 min at 180 °C. This behavior was attributed to curing-induced structural evolution, which regulated interfacial morphology and mechanical interlocking, providing a practical strategy to improve interfacial reliability.