A novel thermal insulation composite material and its preparation method

Abstract

The invention belongs to the technical field of a functional material, and relates to a novel heat dissipation insulating composite material and a preparation method therefor. Specifically, the novel heat dissipation insulating composite material consists of graphite, aluminum and ceramic, and adopts a sandwich structure, wherein a ceramic sheet layer is positioned in the middle, and graphite / aluminum composite sheet layers are positioned on the two sides; and the graphite / aluminum composite sheet layers consist of a graphite sheet layer with pores and aluminum for filling the pores. Integral forming of the graphite, metal aluminum and ceramic is realized by a high-pressure forging method to form the brand new composite material; the composite material has high thermal conduction, high insulativity and enhanced mechanical strength; and raw materials are low in coat, and the preparation method is simple and easy to implement, so that the composite material has high market competitiveness.

Description

technical field [0001] The invention belongs to the technical field of functional materials, and relates to a novel heat-dissipating and insulating composite material and a preparation method thereof. Background technique [0002] For the development of semiconductor integrated circuit chips, LED lighting, IGBT and other fields, the problem of heat dissipation has plagued the industry for many years. As the chip integration becomes higher and higher, how to solve the heat dissipation problem becomes more and more prominent. Due to the constraints of space and chip size, it is destined to only adopt a passive cooling strategy, that is, after the heating body generates heat, the heat is effectively and quickly taken away by using materials with better heat dissipation performance to ensure that the chip can withstand the upper limit of the temperature. work normally within. [0003] As far as the LED lighting industry is concerned, the current development trend is high-power...

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Problems solved by technology

[0005] (1) LED chip materials include gallium nitride (GaN), aluminum oxide (Al 2 o 3 ), sapphire and other materials, the thermal expansion coefficient is about 7ppm / K, so it is required that the matching heat dissipation substrate material should have the same thermal expansion coefficient, while the thermal expansion coefficient of traditional metal materials (such as aluminum, copper, etc.) is 25ppm respectively / K and 17ppm / K, far greater than 7ppm / K, will break at the connection when the temperature rises, resulting in increased thermal resistance and reduced LED life; although ceramic materials have similar thermal expansion coefficients (7.2ppm / K), but The thermal conductivity is not high, and the application is still limited;

[0006] (2) The heat dissipation substrate material of LED requires high thermal conductivity. Although traditional metal materials (such as aluminum with a thermal conductivity of 220W / m K and copper with a thermal conductivity of 390W / m K) have high thermal conductivity performance, but because it does not have insulation, it needs to be used together with other insulating materials, which will greatly reduce its thermal conductivity; although ceramic materials are insulating, their thermal conductivity is generally not high, such as alumina ceramics (based on Al 2 o 3 as the main body) has a thermal conductivity of only 30W / m K, other ceramic materials such as silicon nitride ceramics (based on Si 3 N 4 Although the thermal conductivity of aluminum nitride ceramics (with AlN as the main body) has improved, they are still not stable enough and the cost is high;

[0007] (3) The heat dissipation substrate material of the LED is required to be insulated, and the low-power LED COB module (<50W) can be realized by insulating resin (such as FR4), while the high-power LED COB module (its insulation requires withstand voltage Above 1000V), a certain thickness of insulating layer needs to be added; traditional PCB and DBC substrates are sandwich structures with copper plating on both sides and FR4 resin or ceramics in the middle, and the layers are bonded by welding or thermal conductive silicone grease. decreased

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