High-thermal-conductivity polyimide film and preparation method thereof

Abstract

The invention discloses a high-thermal-conductivity polyimide film and a preparation method thereof, and relates to the technical field of polyimides, boron nitride is subjected to high-temperature calcination, so that the surface of the boron nitride is subjected to micro-oxidation and is negatively charged, and ZIF8 is grown on the surface of the boron nitride through electrostatic interaction to obtain a composite thermal-conductivity filler; an in-situ polymerization reaction is carried out on the composite heat-conducting filler and a polymeric monomer of polyimide in a solvent to prepare polyamide acid; and finally, film casting and heat treatment are carried out to obtain the composite heat-conducting film. According to the invention, ZIF8 is loaded and grown on the surface of BN, on one hand, agglomeration of BN in a PI matrix can be inhibited, so that a good heat conduction path is formed; on the other hand, an organic ligand 2-methylimidazole of ZIF8 has good compatibility with a PI matrix, so that the interface action is inhibited, interface scattering of phonons in the PI matrix can be reduced, and the heat-conducting property of PI is improved; the prepared polyimide film is high in heat conductivity coefficient and good in mechanical property, and has very good popularization and application values.

Description

technical field [0001] The invention relates to the technical field of polyimide, in particular to a polyimide film with high thermal conductivity and a preparation method thereof. Background technique [0002] Polyimide (Polyimide, PI) refers to a class of polymers containing imide rings (-CO-N-CO-) in the main chain, because of its excellent thermal stability, electrical insulation, mechanical properties and Due to its low dielectric properties, it is widely used in many fields such as aerospace, electrical insulation, liquid crystal display, automotive medical care, atomic energy, satellites, nuclear submarines, and microelectronics. However, in these fields, microelectronics are in a high-density and high-speed operation state, which makes electronic components and integrated circuits dissipate a lot of heat, while the intrinsic thermal conductivity of pure PI film is only about 0.16W / (m k), which is not thermal conductivity. The material cannot export heat in time, and...

AI Technical Summary

Problems solved by technology

However, the addition of inorganic fillers will also produce factors that are not conducive to thermal conductivity. First, inorganic fillers are easy to agglomerate, difficult to disperse evenly in polymers, and cannot form good heat conduction channels, so the thermal conductivity is not ideal; the second is inorganic fillers and polymers. The poor compatibility of the inorganic filler will cause a large number of interfaces, which will increase the interface scattering of phonons and limit the thermal conductivity. Therefore, it is very necessary to modify the surface of the inorganic filler.

[0004] The two-dimensional material hexagonal boron nitride, known as "white graphene", was selected as a thermally conductive filler because of its good thermal conductivity of 280W / (m K), but its surface is relatively inert and difficult to be compatible with polymers. , and prone to agglomeration, which limits the thermal conductivity of boron nitride-enhanced polymers