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

Abstract 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.