Benzocyclobutenes: A New Class of High Performance Polymers

All-carbocycle hydrocarbon thermosets with high thermal stability and robust mechanical strength for low-k interlayer dielectrics

Two kinds of hydrocarbon precursors were synthesized and cured at elevated temperatures to give cross-linked all-aliphatic/aromatic-ring polymers with a low dielectric constant for next-generation interlayer dielectrics.

A Fluorinated Thermocrosslinkable Organosiloxane: A New Low-k Material at High Frequency with Low Water Uptake

In order to obtain low-k material with good comprehensive properties, a trifluoromethyl-containing organosiloxane with thermocrosslinkable vinyl and benzocyclobutene groups is designed and synthesized through the Piers-Rubinsztajn reaction. After treating at high temperature, the organosiloxane changed to form a cross-linked polysiloxane (called as c-FSi-BCB). c-FSi-BCB exhibits good dielectric properties with dielectric constant (D_k ) of 2.60 and dielectric loss (D_f ) of 1.49 × 10^-3 at a high frequency of 5 GHz. Importantly, c-FSi-BCB maintains such good dielectric properties and exhibits low water uptake of below 0.076%, even after immersing it in boiling water for 96 h. c-FSi-BCB also displays good thermostability with a 5% weight loss temperature (T_5d ) of 453 °C. These data indicate that this fluorinated organosiloxane is suitable as the matrix resin for the fabrication of devices used in 5G communication.

Synthesis and properties of benzocyclobutene-terminated imide-containing cyano group

Benzocyclobutene (BCB) resins have aroused much interest because of their excellent physical and chemical properties. Unfortunately the temperature required to induce cross-linking in typical BCBs is higher than 250°C, which restricts their applications. In this study, a novel cyano-containing BCB-terminated imide monomer was synthesized through the reaction of 1-cyano-5-amino-benzocyclobutene with 4,4′-oxydiphthalic anhydride. This monomer allows a 50–100°C lower curing temperature in comparison with typical BCBs, and it is highly soluble in various solvents and can easily convert to cured film at 150–200°C. Because of the presence of rigid imide group and strong polar cyano group, the cured film exhibits excellent mechanical strength with tensile strength up to 87.8 MPa, high glass transition temperature up to 350°C, low coefficient of thermal expansion (36.9 ppm K−1), and outstanding planarity with the average surface roughness as low as 0.26 nm.

High-performance intrinsic low-k polymer via the synergistic effect of its three units: adamantyl, perfluorocyclobutylidene and benzocyclobutene

Intrinsic highly cross-linked low-k benzocyclobutene polymer functionalized with adamantyl and perfluorocyclobutylidene.