Preparation method of spherical boron nitride

Abstract

The invention provides a preparation method of spherical boron nitride, which comprises the following steps of: (1) mixing boron nitride powder, a surfactant, carbohydrate and water in a mass ratio of10: (0.05-0.5): (1-10): (50-200), and uniformly stirring to obtain a suspension A; (2) transferring the suspension A into an isostatic pressing stripping machine, and carrying out isostatic pressingstripping; and then carrying out heating treatment under a closed condition, and filtering and drying to obtain powder B; (3) dissolving the powder B and a binder in water, uniformly stirring, and adjusting the pH value to obtain a stable solution C; and (4) introducing the solution C into a spray tower for spray drying to obtain powder, and performing high-temperature calcination to obtain the spherical boron nitride. The spherical boron nitride is high in strength, high in density and low in porosity, and the tap density of the finally obtained spherical boron nitride can reach 0.7-1.0 g / cc.

Description

technical field [0001] The invention relates to the field of thermally conductive and insulating inorganic non-metallic materials, in particular to a preparation method of spherical boron nitride. Background technique [0002] With the development of the times, people have higher and higher requirements for the performance of electronic products, and the update iteration of electronic products is accelerating. At the same time, the heat generation of electronic components is increasing. Often heat sources or devices such as integrated circuit chips are equipped with heat sinks to remove the heat they generate during operation. However, the thermal contact resistance between the heat source or device and the heat sink limits the heat dissipation efficiency of the heat sink. During assembly, a thermally conductive paste, such as silane, or a thermally conductive organic wax is usually applied to create a low thermal resistance path between the mating surfaces of the heat sour...

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Problems solved by technology

Chinese patent CN201410182045.5 discloses a spherical boron nitride and its application. The patent uses a template agent and a hydrothermal method to prepare a spherical precursor, which is calcined at a high temperature to obtain spherical boron nitride with a high specific surface area, and its particle size is 0.2 ~1.5um, the particle size is too small, the specific surface area is large, and its filling amount in the thermally conductive adhesive cannot be increased

The chemical inertness of boron nitride makes the boron nitride spray dry, there is no strong bonding force between the sheets, and the spherical boron nitride obtained after high-temperature calcination has low tap density and low mechanical strength. In the process of adding thermally conductive adhesive, It is easily broken to form lamellar boron nitride, reducing its filling amount in thermally conductive adhesives

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