Thermally conductive composite sheet and method of making the same

Abstract

The invention discloses a heat-conducting composite material sheet, comprising a first aluminum alloy layer, at least one graphite sheet, an aluminum alloy frame and a second aluminum alloy layer, the aluminum alloy frame has at least one opening, and the graphite sheet is positioned on the In the opening of the aluminum alloy frame, the aluminum alloy frame and the graphite sheet are sandwiched between the first aluminum alloy layer and the second aluminum alloy layer, and the first aluminum alloy layer, the graphite sheet and the aluminum alloy frame Diffusion connection between the second aluminum alloy layer, the graphite sheet and the aluminum alloy frame, the graphite sheet is covered by the first aluminum alloy layer, the second aluminum alloy layer and the aluminum alloy frame, forming a overall. The invention also provides a manufacturing method of the heat-conducting composite material sheet. The heat-conducting composite material sheet and the manufacturing method thereof provided by the invention can connect high-heat-conducting aluminum alloy and graphite, and have lower production cost.

Description

Technical field [0001] The present invention relates to the technical field of thermal control, in particular to a thermally conductive composite material sheet with high thermal conductivity and a manufacturing method thereof. Background technique [0002] In the heat dissipation structure of electronic components, forged aluminum alloy materials with higher strength and higher thermal conductivity, such as American brand 6XXX series (6061, 6063), domestic brand LD series aluminum alloy, are often used for heat dissipation fins and heat Shen frame and other structures. 6XXX series aluminum alloy is a kind of medium and high strength aluminum alloy that can be strengthened by heat treatment. It has a series of excellent comprehensive properties: good manufacturability and corrosion resistance, sufficient toughness, can be anodized and colored, and has no stress corrosion cracking tendency. With its high specific strength and good thermal conductivity, it can prepare a variety of...

AI Technical Summary

Problems solved by technology

[0004] The compatibility of aluminum and graphite is very poor, which includes two problems. First, the wettability of liquid aluminum and graphite is poor, and the metal aluminum liquid cannot spread on the graphite substrate.

Secondly, when the synthesis temperature exceeds 500°C, a chemical reaction will occur between aluminum and carbon to form a brittle carbide reaction layer. With the further increase of the synthesis temperature, the chemical reaction will aggravate, seriously weakening the thermal conductivity of graphite itself, and also causing Degradation of Composite Properties

[0005] Traditional hot pressing can produce high-performance materials, but for materials such as pure nitrides, carbides, oxides or borides with a theoretical density close to 100%, especially when high volume fractions of high thermal conductivity ceramics or diamonds, graphite, etc. When mixed with metal matrix, it is difficult to prepare by powder sintering densification or liquid phase processing technology

Moreover, the productivity of this technology is quite limited, the heat treatment temperature is as high as 2200 ° C, the cycle time is usually 6 hours or 12 hours, the production process is complicated, and the production cycle is long

Images