Facile Construction\nof Hyperbranched Polyphenylsiloxane-Modified\nEpoxy Resins with Excellent Low Dielectric Properties for Electronic\nPackaging

The booming development of next-generation communication\ntechnologies\nurgently requires high-performance electronic packaging materials\nwith facile construction. Hereby, We first synthesized hyperbranched\npolysiloxane with phenyl, propyl, and hydroxyl groups as terminals.\nSubsequently, we incorporated it into bisphenol A epoxy resin using\ncovalent cross-linking agents to cure it for electronic packaging\napplications. The manufactured DGEBA/HBPSi/MeTHPA resins not only\nhad a lower curing temperature, which facilitates processing, but\nalso exhibited significantly enhanced toughness, thereby increasing\nthe usage limit of packaging materials. Differential scanning calorimetry\n(DSC) data were utilized to explore the nonisothermal curing behaviors\nof the system. The DSC thermogram exhibited distinct curing stages\nwithin the temperature range of 75–225 °C, and the average\nactivation energies computed using the Kissinger and Ozawa methods\nwere 68.42 and 71.73 kJ/mol, respectively. Additionally, dynamic mechanical\nanalysis (DMA) and fracture morphology analysis demonstrated that\nthe DGEBA/HBPSi/MeTHPA resin had excellent storage modulus, enabling\nit to better resist external impacts, and its fracture surface displays\nductile fracture characteristics. Meanwhile, compared to the pure\nepoxy resins, the impact strength, flexural strength, and elongation\nat break were significantly increased by 153.85, 47.76, and 205.94%,\nrespectively. Notably, the DGEBA/HBPSi/MeTHPA resins have excellent\ndielectric properties and exhibited a low dielectric constant (<i>D</i><sub>k</sub> of 2.82) and dielectric dissipation factor\n(<i>D</i><sub>f</sub> of 0.02050) at 100 MHz. The variation\nof optical parameters and complex dielectric constant of modified\nepoxy resin was also studied by spectroscopic ellipsometry, and the\nresults showed that it has excellent optical properties. The work\ndemonstrates that the DGEBA/HBPSi/MeTHPA resins have the potential\nto be extensively used in the area of electronic packaging in an approach\nthat seems promising.