Bridged-Dialkyl-Silane Modified Thermally Conductive Gel: Fabrication, Properties, and Their Role in Improving Long-Term Performance of Advanced Chips

High-power-density modern electronics demand thermally conductive gel-based thermal interface materials (TIMs) that integrate high thermal conductivity, excellent processability, and long-term reliability, yet conventional monoalkyl silanes fail to balance these requirements in high-filler-loading systems. In this work, a series of novel bridged dialkyl silanes were designed and synthesized to modify fillers for fabricating high-performance TIMs. Systematic investigations demonstrate that BD-C12, bearing two 12-carbon alkyl chains, outperforms all other silanes studied. At a filler loading of 92.5 wt%, the BD-C12-modified TIM strikes an optimal balance between thermal conductivity (7.1 W m−1 K−1) and processability (viscosity of 260 Pa s), while maintaining satisfactory mechanical properties with a tensile strength of 0.08 MPa and an elongation at break of 102%. Compared with traditional monoalkyl counterparts, the dual-site anchoring of BD-C12 constructs stronger filler-matrix bonding that resists moisture erosion and prevents interfacial debonding during long-term aging, as confirmed by simulated packaging reliability tests. Notably, over 96% of initial thermal conductivity is retained after 288 h of uHAST aging. This work provides a promising silane design strategy for developing a high-performance, high-reliability thermally conductive gel with great application potential in advanced electronic heat dissipation.