Low-dielectric reprocessable vitrimers via incorporating fluorine moieties and their pattern ability via direct imprinting

The current research highlights regarding future low-dielectric resins for circuit boards lie in their recyclability and pattern ability. In the present work, we put forward a new idea to simultaneously achieve the recyclability and pattern ability of low-dielectric resins in circuit board. In detail, a series of low-dielectric vitrimers were prepared by copolymerization of fluorinated monomers followed by employing imine cross-linked network. By incorporating fluorine-contained units, the dielectric constant of the vitrimers reached to ∼2.4, while preserving high mechanical strength around 33 MPa. Moreover, after reprocessing three times, the dielectric constants of the PFS-imines remained almost unchanged and 89% of original mechanical strength was recovered. Owing to the increased chain relaxation, PFS-imines can be multiply patterned by directly imprinting at the temperature above Tv. Furthermore, the pattern of PFS-imines is removable and reformed, which may be attributed to their reprocessability. Thus, PFS-imine exhibits pattern ability and recyclability, making it particularly suitable for applications in electronic packaging and circuit boards, compared with that of conventional low-dielectric resins.