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...

The route via the cross-linking of hyperbranched prepolymers has potential advantage to construct low dielectric constant (low-k) resins owing to the enhanced molecular free volume in hyperbranched structure. However, it is still a challenge to prepare hyperbranched resins with good film-forming property and low-k. In this paper, two hyperbranched polycarbosilanes with reactive benzocyclobutene groups were synthesized via hydrosilylation reaction to avoid the generation of Si O bonds for enabling the low polarity of chemical bonds. The spacing groups including phenyl or ethylene were incorporated into the hyperbranched structures, and the effect of the spacing groups on the physicochemical properties of hyperbranched polycarbosilane derived resins were investigated. The phenyl groups were found to effectively decrease the dielectric constant (k), while endowing the resins with good film forming ability and thermostability. The UV/thermally cured phenyl group resin owing to dual crosslinked structure, the patterns would not be deformed significantly during thermally cured process. Both hyperbranched polycarbosilane derived resins could be potential photoresists.

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.

Polycarbosilanes have been considered as potential materials used in electronic packaging and circuit boards owing to their excellent low-dielectric performance. In this work, we prepared new hyperbranched carbosilane oligomers (HCBOs) which were functionalized by benzocyclobutene (BCB) groups. HCBOs can be thermally cured to produce transparent (HCBRs) with low dielectric constant and high thermostability.