Cross-Linking Behavior and Effect on Dielectric Characteristics of Benzocyclobutene-Based Polycarbosiloxanes

The cross-linked low-dielectric-constant material hasgarneredmuch attention in the rapid development of advanced electronics packaging.However, few studies have systematically explored the effects of cross-linkingdensity and cross-linking degree on dielectric properties of benzocyclobutene(BCB)-based polymeric materials. Herein, a series of BCB-based polycarbosiloxaneswith varying cross-linking densities were synthesized through Piers-Rubinsztajnpolycondensation and post-Heck modification. The relationship betweencross-linking behavior and the dielectric characteristics of curedmaterials was systematically explored using both molecular dynamics(MD) simulation and experimental verification. The results revealedthat higher cross-linking density and cross-linking degree resultedin more microbranched structures, which effectively reduced the dielectricconstant and dielectric loss of the materials. Moreover, high cross-linkingdensity enhanced the thermal and dimensional stability and enableda facile tuning of the mechanical property of the materials. Overall,our work offered a facile route to realize cross-linking process ofBCB-based polymeric materials by MD simulation and to investigatethe relationship between cross-linking and comprehensive performances,providing a valuable theoretical and experimental basis for the studyof cross-linked low-dielectric-constant material.