Boron nitride nanosheets synergized with two‐dimensional micron silver sheets to enhance thermal conductivity and insulation of epoxy resin composites

With the rapid progress of the advanced electronic device industry, precision electronic instruments are gradually developing towards miniaturization. In this case, epoxy resin gradually attracts people's attention, but its intrinsic thermal conductivity is not high, and the resulting heat dissipation problem limits the further application of epoxy resin in the field of electronic packaging. Therefore, how to enhance the thermal conductivity of epoxy resins has become an urgent problem in the field of electronic packaging. In this work, BNNS was successfully prepared by stripping h‐BN into a flaky two‐dimensional material, which was added to the epoxy resin as a filler to make the composite material. And on the basis of the above, two‐dimensional micron silver flakes (AgMS) with different mass fractions were added to the composites, and the AgMS/BNNS/EP composites were successfully prepared. When BNNS was 25 wt% and AgMS was 1 wt%, its out‐of‐plane thermal conductivity was enhanced from 0.17 W m−1 K−1 of pure epoxy resin to 0.43 W m−1 K−1. When BNNS was 20 wt% and AgMS was 1 wt%, the breakdown strength was enhanced from 105 kV/mm for pure epoxy to 130 kV/mm. This work provides a new strategy for synthesizing high‐thermal‐conductivity epoxy matrix composites.