Most benzocyclobutene (BCB) resins require a thermal pre-polymerization process to achieve the desired viscosity for application. However, the process is difficult to control because it is time-consuming and requires high...

Low-dielectric-constant polymer materials are widely used in the electronic industry owing to their unique characteristics. Benzocyclobutene (BCB) resin is one such material with excellent dielectric properties and thermal stabilities. In this work, a novel BCB-functionalized monomer (DCPDNO-BCB) was synthesized from 2,6-dimethyl phenol-DCPD novolac (DCPDNO) and 4-Bromobenzocyclobutene through Ullmann coupling. The structure of DCPDNO-BCB was characterized by 1 H NMR, 13 C NMR, and ESI-MS, and poly(DCPDNO-BCB), obtained by ringopening and subsequent Diels-Alder reaction at the appropriate temperature, was found to exhibit low dielectric properties (k = 2.53 at 10 MHz), low water absorption, high thermal stability (T d5 = 430 C), and good film flatness.

A benzocyclobutene (BCB) monomer containing carbosilane (CS‐BCB) was successfully synthesized from 4‐vinyl benzocyclobutene (4‐VBCB) and 3,6‐bis(dimethylsilyl)benzocyclobutene (3,6‐D(DMHS)BCB) by hydrosilylation in the presence of Karstedt's catalyst. As an improvement to the conventional synthesis method, the carbosilane is obtained in only two steps. In addition, this method avoids the use of halogens and Grignard reagents, which are expensive and environmentally damaging. After ring‐opening polymerization, the resultant cured CS‐BCB resin shows excellent thermal and dielectric properties; specifically, the 5 % weight loss temperature (T5%) is 435 °C, the dielectric constant (Dk) is 2.36, and the dielectric loss (Df) is less than 10−3 at 10 MHz. Thus, this polymer has enormous potential as a high‐performance electronic interlayer material.