Simultaneous improvement of glass transition temperature and dielectric properties of epoxy resin through novel curing agent molecular designs

With the development of third-generation SiC semiconductor power devices, the thermal resistance and dielectric properties of traditional epoxy resins can no longer meet the demands of high-temperature and high-voltage operating environments. To solve this problem, a novel epoxy resin curing agent was designed in this study. Diaminodiphenyl sulfone (DDS) was used as the raw material; a substitution reaction was carried out with a trifluoromethylating electrophilic reagent [1-trifluoromethyl-1,2-benzoxazol-3(1H)-one] to obtain the novel epoxy curing agent (DDS-CF3). After curing, a highly cross-linked epoxy resin having a glass transition temperature of 312.5 °C and an AC breakdown field strength of 144.3 kV/mm was obtained. The epoxy resin maintained a low dielectric constant and low loss characteristics within the frequency range of 101-106 Hz, demonstrating excellent potential as an insulating material for semiconductor power device packaging.