A kind of directional ultra-high thermal conductivity, high-strength graphite-copper composite material and its preparation method and application

Abstract

The invention relates to a graphite-copper composite material with directional superhigh thermal conductivity and high strength, its preparation method and application. Specifically, the composite material is sintered by hot pressing and sintering of graphite sheets and copper layers arranged in parallel, and the thermal conductivity of the composite material along the direction parallel to X-Y is the same as that along the direction perpendicular to X-Y. The ratio of the thermal conductivity in the -Y direction is ≥ 4, and the thermal conductivity of the composite material along the X-Y direction is ≥ 500W / m·K, wherein the X-Y direction is parallel to the graphite sheet and orientation of the copper layer. The invention also discloses a preparation method of the composite material. In the composite material, the graphite sheets are highly oriented and the copper layer is uniformly distributed between the graphite sheets, so the composite material has very high thermal conductivity and a low thermal expansion coefficient. The preparation method is simple, low in cost and very suitable for large-scale popularization.

Description

Technical field [0001] The present invention relates to the field of thermally conductive materials, in particular to a directional ultra-high thermal conductivity, high-strength graphite-copper composite material, and a preparation method and application thereof. Background technique [0002] With the rapid development of high-power, light-weight, and miniaturization of semiconductor components, the heat generated per unit area is getting higher and higher, and the effective heat dissipation area is declining. Heat dissipation has become an obstacle to high-power electronic devices and high-power solid-state lighting devices. , Ultra-large-scale and ultra-high-speed integrated circuits, and even the bottleneck of the development of the entire information industry. These high-power components and systems urgently require thermally conductive materials to have better thermal conductivity, a thermal expansion coefficient that matches the semiconductor chip material (Si or GaAs), su...

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Problems solved by technology

[0009] The above-mentioned various methods such as selection of scaly copper powder, chemical copper plating, shock vibration and other methods to obtain the direction consistency of graphite sheets, although the thermal conductivity of the composite material has been improved to a certain extent, there are still various problems, such as scales The selection of copper powder and the introduction of subsequent special processes have greatly increased the production cost and process complexity; and although the electroless copper plating process has improved the uniform distribution of metallic copper in graphite-copper composites to a certain extent, it is chemically Various compound ions are inevitably introduced during the copper plating process, which has a great influence on the stability of the composite material in humid air; although shock vibration can improve the arrangement of graphite in a specific direction, it is limited to improving the In the lamellar direction of single flake graphite powder, when graphite and copper powder are mixed together, due to the density difference of about 4 times between graphite and metal copper powder, in this vibration mode, copper powder is easy to move in the mixture. Bottom deposition; in high volume fraction graphite-copper composites, metal copper is more difficult to form a continuous whole, so the role of metal copper is only to fill the pores between graphite and graphite

In fact, if the copper powder accumulates at the bottom of the mixture, the uniformity of the distribution of metallic copper in the composite material cannot be guaranteed at all, which leads to a significant decrease in the density of the composite material, and finally causes the thermal conductivity of the composite material to not be obtained to a large extent. improvement

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