Low-temperature-curable and photo-patternable benzocyclobutene-derived aggregation-induced emission-active polymer dielectrics

The high curing temperatures required for traditional benzocyclobutene (BCB) materials have posed limitations on their applicability in high-temperature-sensitive fields. To address this challenge, our work focuses on the synthesis of a novel tetraphenylethylene (TPE)-functionalized BCB monomer, TPE–BCB, achieved through the introduction of an ether bond onto the BCB's four-membered ring via Williamson reaction. TPE–BCB demonstrates remarkable low-temperature curing properties, characterized by a ring-opening peak temperature of 190°C, representing a reduction of 60°C compared to conventional BCBs. Fully cured TPE–BCB resins exhibit exceptional dielectric and mechanical properties, coupled with minimal water absorption. Additionally, the incorporation of TPE with aggregation-induced emission characteristics enhances the resins’ luminescence and photolithographic capabilities. Notably, our TPE–BCB resins achieve impressive photolithography performance with a resolution ratio of up to 10 μm. In contrast to conventional BCB-functionalized resins, TPE–BCB offers the dual advantage of low-temperature curing and luminescence. This development marks a significant step in the advancement of low-temperature curing BCB materials and serves as a pioneering example in the realm of multilayer wafer bonding materials.