Electromagnetic interference shielding device comprising a flame retarding, thermal interface material composite, and method for preparation thereof

An electromagnetic interference (EMI) shielding device comprising a flame retarding, thermal interface material composite with shielding effectiveness of 30-50 dB at a frequency range of 0 to 10 GHz, a through plane thermal conductivity of no less than 30 W/mK and an in-plane thermal conductivity of no less than 10 W/mK, a dielectric withstanding voltage of no less than 1 kV/mm, the composite comprising:

• at least a first layer of self-aligned, carbon-based materials formed on at least one dielectric layer having a carbon content of about 85 to 99.9% associated with superparamagnetic particles with magnetic field strength of 60-90 amu/g such that an inclined angle between the carbon-based materials and a horizontal plane of the dielectric layer is adjustable between 90 and 45 degrees in the presence of less than 1 Tesla of magnetic field;
• at least a second layer of fillers comprising a blend of dielectric isotropic heat transfer materials with a thermal or UV curable polymer or phase change polymer,
• the first layer comprising a plurality of ceramic fillers associated with a polymer to form a polymer matrix,
• each of the self-aligned, carbon-based materials having an aspect ratio of 3:1 to 6:1 and an average particle size between 0.1 and 1.0 mm,
• the superparamagnetic particles having an average particle size of less than 10 μm, magnetic field strength of about 60 to 90 amu/g and providing the self-aligned driving force, carbon-based materials with an adjustable inclined angle between 90 and 45 degrees about the horizontal plane of the dielectric layer in the presence of less than 1 Tesla of magnetic field, wherein the concentration of the superparamagnetic particles is 2-5 wt. % to the weight of carbon-based materials,
• at least 20% of the first layer overlaps and at least 20% of the second layer when the carbon-based materials are self-aligned in the presence of the magnetic field and tilted to an angle from 0 to about 45 degrees against the direction of the magnetic field at the same plane.