Method for preparing high-thermal conductivity polyimide/magnesium oxide composite film

Abstract

The invention discloses a method for preparing a high-thermal conductivity polyimide / magnesium oxide composite film. The method comprises following steps of (1) dissolving monomer diamine into an organic solvent, stirring to dissolve so as to form a mixed solution; (2) adding monomer dianhydride of the same molar ratio into the solution of step (1), adding a nanometer heat conduction material, mixing uniformly; (3) synthesizing the mixed system of step (2) into nanometer heat conduction material doped polyamide acid resin under conditions that the temperature is 45-55DEG C and reaction time is 7-12 hours; (4) tape casting the polyamide acid resin of step (3) on a stainless steel band, drying to form a cast film, carrying out imidization on the cast film at 350-460DEG C, so as to prepare the polyimide / magnesium oxide composite film. The magnesium oxide inorganic filler is treated on the surface, so as to form effective bonding at the interface, so that thermal contact resistance is reduced, the heat conducting property of the magnesium oxide inorganic filler is improved, and the heat conducting property of the composite material is improved.

Description

technical field [0001] The invention relates to the technical field of polymer insulating packaging materials, in particular to a method for preparing a high thermal conductivity polyimide / magnesium oxide composite film used in industries such as printed circuit boards, microelectronics, and high-temperature-resistant flexible printed circuit substrates . Background technique [0002] Insulating materials are widely used in electronic components, integrated circuits and other fields. With the advancement of science and technology, the electronic integration industry is advancing by leaps and bounds, and related electronic products are increasingly becoming thinner and smaller, which makes their operating frequency increase sharply. To operate stably in the environment and to dissipate excess heat in time, a heat-conducting insulating material with high heat dissipation performance, reliable operation, and good comprehensive performance is required, so that it can not only pl...

AI Technical Summary

Problems solved by technology

[0003] Ordinary polyimide thick film has good insulation properties, but its thermal conductivity is poor, about 0.18W m -1 k -1 , the existing defect is that it is easy to cause circuit heating, difficult to dissipate, circuit temperature rise and other undesirable phenomena during the high-density operation and high-speed process of electronic components, and the reliability and durability of the use are poor. Thermal conductivity is of great significance to its application and life

[0004] The existing technology mainly adopts the following methods to improve the thermal conductivity of polymers: First, based on the theory of particle thermal conductivity, a polymer with a high degree of orientation is synthesized through a parallel high-magnification stretching process. The problem with this method is that the equipment requirements Higher, and when the tensile strength reaches a certain value, the film will break; the second is to use polymers with excellent thermal conductivity such as polyacetylene and polypyrrole as doping agents to prepare composite materials with high thermal conductivity. Crystalline highly oriented polymers are difficult to prepare, and it is difficult to achieve large-scale production; the third is to use the inorganic filler doping method, that is, doping alumina, aluminum nitride, boron nitride, graphite and other fillers with high thermal conductivity into the polymer In polymers, composite materials with improved thermal conductivity are obtained. This method has low cost of inorganic fillers and is easy to process and shape. It can be applied to some special fields after proper treatment, but magnesium oxide has not been used in the prior art. Doping technology as a filler