This invention belongs to the technical field of thermal management and insulation materials for electronic and
power equipment. Specifically, it discloses a controllable dense gradient
boron nitride semi-cured thermally conductive and insulating film and its preparation method. This invention adopts a formulation-structure-process synergistic approach, in which multi-morphological
hexagonal boron nitride (microspheres / sheets / nanotubes) after
plasma activation and
silane coupling treatment are hierarchically filled into a
resin matrix, and then a multi-layer gradient structure
film material is formed through controllable densification. This results in a
film material that simultaneously possesses high
thermal conductivity in the thickness direction, excellent electrical insulation, structural adhesion, and
mass production processability. It is suitable for photovoltaic inverters, traction / auxiliary inverters for
new energy vehicles, IGBT / SiC / GaN power modules, and interface thermal management and structural adhesion between PCBs and heat sinks.