UV-curable low dielectric siloxane-benzocyclobutene resins via introducing carbosilane groups

Low dielectric UV-curable resins are compatible with photolithography and 3D printing technique, and have great potential for use in inter-layered packaging and antenna. However, it is still a challenge to construct photoactive structure which combines low dielectric properties. In the present work, we propose a new type of low dielectric UV-curable resins by employing photoactive silacyclobutene groups. This low dielectric resins were prepared by UV/thermally curing of siloxane-benzocyclobutene oligomers (SBCOs). Oligomeric SBCOs were prepared by the simple hydrolysis-polycondensation of 1,1-dichlorosilacyclobutane followed by termination of the benzocyclobutene groups. In this way, silaycyclobutene and benzocyclobutene groups were simultaneously introduced into the resins to enable UV and thermally curing of SBCOs. The molecular weight of SBCOs were tuned by the ratio of 1,1-dichlorosilacyclobutane and benzocyclobutene-containing monomer. The cured siloxane-benzocyclobutene resins were thermostable, mechanically strong, and had low dielectric properties.