METHOD FOR OBTAINING A HEAT-DISSIPATING ANISOTROPIC STRUCTURAL DIELECTRIC COMPOSITE MATERIAL AND A HEAT-DISSIPATING ANISOTROPIC STRUCTURAL DIELECTRIC COMPOSITE MATERIAL Russian patent published in 2022 - IPC C09K5/00 H01L23/36 C08L61/10 C08K3/38 C08K3/28 

FIELD: composite materials.

SUBSTANCE: invention relates to heat-dissipating dielectric polymer composite materials for various branches of electronics (microelectronics, vacuum devices, plasma and laser technologies). The corresponding heat-dissipating structural materials are used, among other things, for the manufacture of cooling radiators and heat-dissipating housings. The proposed solution relates to technologically low-cost methods for obtaining a heat-dissipating anisotropic structural dielectric composite material consisting of hexagonal boron nitride and thermosetting phenol-formaldehyde resin as a polymer matrix obtained by liquid-phase mixing, including using high-speed mechanical dispersion, followed by solvent removal and uniaxial pressing into a metal matrix at a temperature of 120-180°C, for 60-90 minutes, at a pressure of 40-80 MPa, followed by cooling to room temperature and machining. The heat-dissipating anisotropic structural dielectric composite material has a maximum thermal conductivity when measured in the direction of the heat flow perpendicular to the axis of application of the load during pressing, 2.4-18.5 W/(m⋅K), a minimum thermal conductivity when measured in the direction of the heat flow parallel to the axis of application of the load during pressing, 1.5-10.0 W/(m⋅K), moreover, the anisotropy of thermal conductivity (the ratio of the maximum and minimum values of thermal conductivity in mutually perpendicular directions) with any method for implementing the invention is 1.45 or more. The material is dielectric, and its electrical resistivity at direct current is at least 10⁹ Ohm⋅cm, and the dielectric constant at a frequency of 1 kHz is no more than 10, is structural with a compressive strength of at least 20 MPa and an elastic modulus of at least 4.5 GPa and can be mechanically processed into products by all traditional methods, has high thermal properties. The heat-dissipating anisotropic structural dielectric composite material has a BN filler content of 50 vol. %, modulus of elasticity is no less than 12.5 GPa and compressive strength is no less than 60 MPa, thereby it is suitable for the manufacture of highly loaded heat-dissipating structures. With a BN filler content of 85 vol. %, the mass loss of the sample when heated to 250°C by thermogravimetric analysis is less than 0.2%, and the long-term temperature stability is 422°C, the coefficient of thermal expansion is no more than 25⋅10^-6 K^-1, thereby it is suitable for cooling highly heat-loaded electronic components in conditions of significant local overheating.

EFFECT: new solution to obtain a heat-dissipating anisotropic structural dielectric composite material.

8 cl, 1 dwg, 1 tbl