Benzocyclobutene

Colorless liquid

Benzocyclobutene was used as the adhesive bonding material in adhesive wafer-level bonding technique. Photosensitive benzocyclobutene has been widely used as dielectric material in multilayer packaging applications. It was used in fabrication of high density multilayer interconnect structures using gold metallization and polymer interlayer dielectric.

Benzocyclobutene (BCB) is composed of a benzene ring fused to a cyclobutane ring (chemical formula C8H8). It is frequently used to create photosensitive polymers. BCB-based polymer dielectrics may be spun on various substrates, with good step coverage properties that make them useful to planarize uneven topographies. Applications include wafer bonding, optical interconnects, semihermetic package sealing, passivation, and low-k dielectrics. BCB has been also reported as a material with good biocompatibility, being used in intracortical neural implants and other biomedical applications.

ChEBI: A carbobicyclic compound that is benzene fused to a cyclobutane ring.

Journal of the American Chemical Society, 97, p. 5600, 1975 DOI: 10.1021/ja00852a057
The Journal of Organic Chemistry, 38, p. 3412, 1973 DOI: 10.1021/jo00959a039
Tetrahedron Letters, 16, p. 1893, 1975

The Initial Threshold Screening Level (ITSL) for benzocyclobutene is 220 μg/m3 with an annual averaging time.