Preparation method of heat-conducting gasket with high normal heat conductivity and high elasticity

Abstract

The invention belongs to the technical field of preparation of heat conduction materials, and discloses a preparation method of a heat-conducting gasket with high normal heat conductivity and high elasticity. The preparation method comprises the following steps: (1) with a graphite film or a graphene film as a filler, carrying out plasma modification to obtain a first modified graphite film or graphene film; (2) hydroxylating the first modified graphite film or graphene film, and grafting a hydrolyzed coupling agent to obtain a second modified graphite film or graphene film; (3) coating the surface of the second modified graphite film or graphene film with polyolefin, carrying out pre-curing treatment, and conducting stacking by adopting a laminating process to obtain a graphite film or graphene film / polyolefin multi-layer composite structure formed body; and (4) after hot-pressing treatment, conducting cutting along a direction vertical to the upper surface and the lower surface of the multi-layer composite structure formed body to obtain the heat-conducting gasket. The obtained heat-conducting gasket is good in heat-conducting property, and when a filler content reaches 94.3%, the heat conductivity of the gasket reaches 726.1 W / (m.K).

Description

technical field [0001] The invention belongs to the technical field of heat-conducting material preparation, and in particular relates to a method for preparing a heat-conducting gasket with high normal thermal conductivity and high elasticity. Background technique [0002] With the miniaturization, high density and high power of integrated circuits, the heat dissipation of electronic components has seriously restricted the development of the integrated circuit industry. According to statistics from the U.S. Air Force Electronics Industry Department: About 55% of the failures of electronic products are caused by overheating and heat-related problems. Therefore, the problem of thermal management of electronic devices needs to be solved urgently. [0003] Thermal interface material is a key material to solve the heat dissipation of electronic devices. It is used to fill the gap between device interfaces and reduce heat transfer resistance. The main types of thermal interface...

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Problems solved by technology

[0006] The following disadvantages exist in the preparation of thermally conductive composite materials in the prior art. 1. The disadvantage of the ice template method is that the filler volume content is low, and the mechanical strength of the three-dimensional skeleton is not enough. In order to enhance the mechanical strength of the three-dimensional skeleton, it is usually necessary to add polymer adhesives. thereby reducing the heat transfer performance of the entire three-dimensional skeleton

2. The volume fraction of the three-dimensional graphene skeleton obtained by the hydrothermal method is not ideal, and it is generally difficult to exceed 25vol%, which affects the improvement of thermal conductivity

First of all, the bonding force between graphene film layers is weak and easy to delaminate, so it is difficult for thermal pads to pass reliability tests

Secondly, it is difficult to control the polymer content and uniformity in the way of glue filling or gluing, usually the polymer content is very low, and the overall mechanical properties are poor

Although the patent of Matsushita Electric Works of Japan also uses lamination technology, it is necessary to prepare an in-plane oriented composite film first.

In terms of process, it is more complicated than the process of directly using graphene film, and in order to make the composite material film better bonded, the polymer requirements are higher

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