A Review on the Design, Preparation, and Performance Control of Low Dielectric Constant Polybenzoxazine-Based Materials

With the rapid development of technologies such as 5G/6G communication, artificial intelligence, and high-performance computing, electronic devices are continuously evolving toward higher frequencies, higher speeds, higher integration, and miniaturization. This has placed greater demands on the dielectric properties and thermal stability of the substrates and interconnection media. Traditional low dielectric materials such as polyimide, cyanoacrylate, and benzocyclobutene, due to their poor dielectric stability, easy bubble formation during curing, and high costs, have become unable to meet the future application requirements. Polybenzoxazine (PBZ), as a new type of thermosetting resin, has become a research hotspot for low dielectric and high-performance materials due to its flexible molecular design, near-zero volume shrinkage, and excellent heat resistance. This article reviews the latest research progress of low dielectric constant (Dk) PBZ-based materials. Starting from the fundamental principles of reducing Dk and the molecular characteristics of benzoxazine, this paper focuses on elaborating three major approaches to achieving ultralow Dk: molecular structure design, blending and composite strategies, and nanocomposite and hybrid materials. It systematically analyzes the influence mechanisms of various methods on dielectric, thermal stability, mechanical, and water absorption properties. Finally, we summarize the current challenges and look forward to the future development direction, providing theoretical and technical references for the development and application of the new generation of high-performance low dielectric materials.