Enhancing Adhesion and Peel Strength for Fine Line Design on FCCSP Package

This study investigates the critical factors influencing the adhesion performance of FCCSP substrates, focusing on enhancing fine-line designs. By systematically examining the effects of filler content in Bismaleimide-Triazine (BT) resin, copper foil surface roughness, and baking conditions, we identified key parameters that significantly improve the peel strength between the prepreg (PP) layer and the electroless copper layer. The results indicate that reducing filler content, optimizing surface roughness, and implementing specific baking processes enhance mechanical adhesion and substrate reliability, thereby supporting fine-line pitch down to 22 μm while maintaining high peel strength. The findings demonstrate the potential of the FCCSP process, independent of the Electroless Semi-Additive Process (eSAP), to meet stringent industry requirements for high-density electronic packaging. This study provides a cost-effective and reliable pathway for advancing FCCSP technology, meeting the growing demands for miniaturization and multifunctionality in modern electronic devices.