A diamond composite material and preparation method thereof

Abstract

The present invention discloses a diamond composite material and a preparation method thereof, the method comprising the steps of: providing diamond powder and heat-conducting metal powder; mixing the diamond powder and the heat-conducting metal powder and spreading them in a metal cup, placing a heat-conducting metal sheet, and obtaining an assembled component; or placing the heat-conducting metal sheet in a metal cup, mixing the diamond powder and the heat-conducting metal powder and laying them on the heat-conducting metal sheet, and then placing the heat-conducting metal sheet to obtain an assembled component; vacuum-treating the assembled component at a first preset temperature; placing the vacuum-treated component into a pyrophyllite synthesis component, sintering at a preset pressure and a second preset temperature, and obtaining a diamond composite material. The present invention prepares a diamond composite material having high hardness and high thermal conductivity of both diamond and high thermal conductivity metal by sintering diamond powder and heat-conducting metal powder at high temperature and high pressure, and at the same time, adjusting the content of diamond powder can achieve adjustable thermal expansion coefficient of the diamond composite material.

Description

Technical Field

[0001] The invention relates to the technical field of superhard material manufacturing, and in particular to a diamond composite material and a preparation method thereof. Background Art

[0002] With the rapid development of electronic information technology, the integration of electronic and semiconductor devices is getting higher and higher, and the heat flux density generated is getting larger and larger, resulting in a higher temperature rise of components. Research results show that the reliability of semiconductor components decreases by 50% for every 10°C increase in temperature; about 55% of modern microelectronic circuit failures are caused by thermal damage. Therefore, how to achieve efficient heat dissipation is the key to ensuring the stability and reliability of electronic equipment operation.

[0003] Selecting thermal management materials with excellent thermal conductivity as heat sinks or heat dissipation devices can coordinate the gradually increasing power density with the temperature difference of the surrounding environment, achieve efficient heat dissipation and reduce the mismatch of thermal expansion coefficient with chip materials, and improve the stability and reliability of the system. Ideal thermal management materials should have ultra-high thermal conductivity (TC) and a matching thermal expansion coefficient. Metal matrix composites have been fully developed in the field of thermal management due to their designability of structure and performance. Among them, diamond / metal composites have become a research hotspot and development direction in the field of thermal management due to their advantages such as low density, high thermal conductivity and adjustable thermal expansion coefficient. The quality of thermal conductivity of diamond / metal composites depends largely on the preparation process. Therefore, composite process methods are particularly important in material research. There are many preparation methods for metal matrix composites, mainly including spark plasma sintering (SPS), vacuum hot pressing sintering, pressureless infiltration, vacuum gas pressure infiltration and squeeze casting. However, these methods cannot achieve high thermal conductivity and adjustable thermal expansion coefficient of diamond composites.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a diamond composite material and a preparation method thereof, aiming to solve the problem that the existing preparation method of diamond composite materials cannot achieve high thermal conductivity and adjustable thermal expansion coefficient of diamond composite materials.

[0006] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0007] A method for preparing a diamond composite material, comprising the steps of:

[0008] Provide diamond powder and thermal conductive metal powder;

[0009] The diamond powder and the heat-conducting metal powder are mixed and spread on a metal cup, and a heat-conducting metal sheet is placed in the cup to obtain an assembled component; or, a heat-conducting metal sheet is placed in a metal cup, the diamond powder and the heat-conducting metal powder are mixed and spread on the heat-conducting metal sheet, and then the heat-conducting metal sheet is placed in the cup to obtain an assembled component;

[0010] performing vacuum treatment on the assembled components at a first preset temperature;

[0011] The vacuum-treated component is loaded into a pyrophyllite synthesis component, and sintered at a preset pressure and a second preset temperature to obtain the diamond composite material.

[0012] The method for preparing the diamond composite material, wherein the diamond composite material is a double-layer structure or a sandwich structure.

[0013] In the method for preparing the diamond composite material, the diamond powder is diamond powder with a thermally conductive metal film coated on the surface.

[0014] The method for preparing the diamond composite material, wherein the thermally conductive metal film is one of a copper film, an aluminum film, a silver film, a gold film, a copper alloy film, an aluminum alloy film, and a silver alloy film, and the thermal conductivity of the thermally conductive metal film is 200 to 500 W / mK.

[0015] The method for preparing the diamond composite material, wherein the heat-conducting metal powder is selected from one of copper powder, aluminum powder, silver powder, gold powder, copper alloy powder, aluminum alloy powder, and silver alloy powder, and the thermal conductivity of the heat-conducting metal powder is 200 to 550 W / mK;

[0016] The heat-conducting metal sheet is selected from one of a copper sheet, an aluminum sheet, a silver sheet, a gold sheet, a copper alloy sheet, an aluminum alloy sheet, and a silver alloy sheet, and the thermal conductivity of the heat-conducting metal sheet is 200 to 550 W / mK.

[0017] The method for preparing the diamond composite material, wherein the first preset temperature is 500-700° C., and the vacuum treatment time is 2-10 hours.

[0018] In the method for preparing the diamond composite material, the second preset temperature is 800-2000° C., and the preset pressure is 2-10 GPa.

[0019] The method for preparing the diamond composite material comprises the following steps: the diamond powder and the heat-conducting metal powder are mixed in a weight ratio of 85-99.9:0.01-15; the particle size of the diamond powder is 10-500 μm; the particle size of the heat-conducting metal powder is 1-20 μm; and the thickness of the heat-conducting metal sheet is 0.5-5 mm.

[0020] In the method for preparing the diamond composite material, the material of the metal cup is one or more of molybdenum, niobium, zirconium and tantalum.

[0021] A diamond composite material, wherein it is prepared by the method described in the above scheme of the present invention.

[0022] Beneficial effects: The present invention discloses a diamond composite material and a preparation method thereof. The diamond composite material is prepared by sintering diamond powder and heat-conducting metal powder together under high temperature and high pressure, so that the finally prepared diamond composite material can have the high hardness and high thermal conductivity of diamond and heat-conducting metal. At the same time, by adjusting the content of diamond powder, the thermal expansion coefficient of the prepared diamond composite material can be adjusted. The preparation method of the present invention has the advantages of simple preparation technology and strong repeatability of operation. The prepared diamond composite material has excellent thermal conductivity, high density and good repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention provides a flow chart of the preparation method of a diamond composite material.

[0024] Figure 2 Schematic diagram of a diamond composite material sample prepared in an embodiment of the present invention.

[0025] Figure 3 The figure is a schematic diagram of the structure of a double-layer diamond composite material according to an embodiment of the present invention.

[0026] Figure 4 The figure is a schematic diagram of the structure of a sandwich diamond composite material according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention provides a diamond composite material and a preparation method thereof. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] See also Figure 1 The present invention provides a method for preparing a diamond composite material, which comprises the steps of:

[0029] S10, providing diamond powder and thermal conductive metal powder;

[0030] S20, mixing the diamond powder and the heat-conducting metal powder and spreading them on a metal cup, and putting a heat-conducting metal sheet in to obtain an assembled component; or, putting a heat-conducting metal sheet in a metal cup, mixing the diamond powder and the heat-conducting metal powder and spreading them on the heat-conducting metal sheet, and then putting the heat-conducting metal sheet in to obtain an assembled component;

[0031] S30, performing vacuum treatment on the assembled components at a first preset temperature;

[0032] S40, loading the vacuum-treated assembly into a pyrophyllite synthesis assembly, and sintering the assembly at a preset pressure and a second preset temperature to obtain the diamond composite material.

[0033] Specifically, the present invention prepares a diamond composite material by sintering diamond powder and heat-conducting metal powder together under high temperature and high pressure, so that the finally prepared diamond composite material can have high hardness and high thermal conductivity of diamond and heat-conducting metal, and the thermal expansion coefficient of the prepared diamond composite material can be adjusted by adjusting the content of diamond powder. The preparation method of the present invention has the advantages of simple preparation technology and strong repeatability. The prepared diamond composite material has excellent thermal conductivity, high density and good repeatability. The prepared diamond composite material sample is as follows Figure 2 shown.

[0034] In some embodiments, the diamond composite material is a double-layer structure or a sandwich structure. When the step S20 is to mix the diamond powder and the thermally conductive metal powder and spread them on a metal cup, put a thermally conductive metal sheet in, and obtain an assembled component, the diamond composite material finally obtained is a double-layer diamond composite material; when the step S20 is to put a thermally conductive metal sheet into a metal cup, mix the diamond powder and the thermally conductive metal powder and spread them on the thermally conductive metal sheet, and then put a thermally conductive metal sheet in to obtain an assembled component, the diamond composite material finally obtained is a sandwich diamond composite material; the double-layer diamond composite material and the sandwich diamond composite material have the same technical effect and are prepared according to different needs, that is, the diamond composite material is designed with a sandwich or double-layer structure while ensuring the high thermal conductivity of the diamond powder itself so that the diamond composite material has high thermal conductivity to meet the needs of different usage scenarios.

[0035] In some embodiments, the diamond powder is diamond powder with a thermally conductive metal film coated on the surface.

[0036] Specifically, the thermal conductivity of the diamond powder can be improved by pre-treating the diamond powder and coating the surface with a thermally conductive metal film. The thermal conductivity can be improved while the entry of catalytic metals such as Co during the subsequent high temperature and high pressure sintering of PDC can be hindered by coating the thermally conductive metal film.

[0037] The diamond powder used in the present invention is single crystal diamond powder. In some other embodiments, the diamond powder needs to be pretreated to remove impurities before the surface of the diamond powder is plated with a thermally conductive metal film. The purchased diamond powder can also be pretreated to remove impurities and then used directly without being plated with a thermally conductive metal film. The steps of pretreatment to remove impurities are specifically: acid treatment and alkali treatment of the diamond powder and washing with deionized water to neutrality to remove metal binders, impurities, etc. in the diamond powder, and pure diamond powder is obtained after pretreatment.

[0038] In some embodiments, the thermally conductive metal film is one of a copper film, an aluminum film, a silver film, a gold film, a copper alloy film, an aluminum alloy film, and a silver alloy film, and the thermal conductivity of the thermally conductive metal film is 200 to 500 W / mK. By selecting a material with a thermal conductivity of 200 to 500 W / mK as the thermally conductive metal film material, it can meet the standard for plating and can improve the thermal conductivity of the diamond powder.

[0039] In some embodiments, the thermally conductive metal powder is selected from one of copper powder, aluminum powder, silver powder, gold powder, copper alloy powder, aluminum alloy powder, and silver alloy powder, and the thermal conductivity of the thermally conductive metal powder is 200-550 W / mK; the thermally conductive metal sheet is selected from one of copper sheet, aluminum sheet, silver sheet, gold sheet, copper alloy sheet, aluminum alloy sheet, and silver alloy sheet, and the thermal conductivity of the thermally conductive metal sheet is 200-550 W / mK. Materials with a thermal conductivity within the range of 200-550 W / mK can make the final diamond composite material have suitable thermal conductivity and can also avoid negative impact on the performance of the diamond composite material.

[0040] In some embodiments, the first preset temperature is 500-700° C., and the vacuum treatment time is 2-10 hours.

[0041] In some embodiments, the second preset temperature is 800-2000° C., and the preset pressure is 2-10 GPa.

[0042] In some embodiments, the diamond powder and the thermally conductive metal powder are mixed in a weight ratio of 85-99.9:0.01-15, the particle size of the diamond powder is 10-500 μm, the particle size of the thermally conductive metal powder is 1-20 μm, and the layer thickness of the thermally conductive metal sheet is 0.5-5 mm. By controlling the amount of diamond powder added, the thermal expansion coefficient can be adjusted. The more diamond powder is added, the smaller the thermal expansion coefficient of the obtained diamond composite material is, and the closer the amount of diamond powder added is to the amount of thermally conductive metal powder added, the larger the thermal expansion coefficient of the obtained diamond composite material is.

[0043] In some embodiments, the material of the metal cup is one or more of molybdenum, niobium, zirconium, and tantalum. Shielding material is necessary in the preparation process of diamond composite materials. Therefore, this embodiment preferably uses molybdenum, niobium, zirconium, and tantalum as the material of the metal cup.

[0044] In some embodiments, after step S40, the step of: performing subsequent processing on the sintered diamond composite material according to the target size; that is, after decompression and cooling, taking out the sintered thermally conductive diamond composite material and performing subsequent machining to the target size is further included.

[0045] The present invention also provides a diamond composite material prepared by the method described in the above scheme of the present invention, which comprises a diamond thermal conductive metal composite material layer and a thermal conductive metal material layer.

[0046] Specifically, the diamond thermal conductive metal composite material layer is composed of diamond and thermal conductive metal, and the thermal conductive metal material layer is composed of thermal conductive metal sheets. When the diamond composite material is a double-layer structure, it includes a diamond thermal conductive metal composite material layer and a thermal conductive metal material layer; when the diamond composite material is a sandwich structure, it includes two thermal conductive metal material layers and a diamond thermal conductive metal composite material layer sandwiched between the two thermal conductive metal material layers.

[0047] The hardness of the diamond composite material prepared by the method of the present invention is improved by 50% to 80% on the original basis, and the thermal conductivity is improved by 20% to 40%.

[0048] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and are only used to illustrate the present invention but not to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Example 1

[0050] A method for preparing a double-layer diamond composite material comprises the steps of:

[0051] S10, providing diamond powder and thermally conductive metal powder coated with a thermally conductive metal film on the surface;

[0052] S20, mixing the diamond powder coated with a heat-conducting metal film on the surface and the heat-conducting metal powder in a mass ratio of 99:1, putting the mixture into a niobium cup, and placing a heat-conducting metal sheet therein to obtain an assembled component;

[0053] S30, subjecting the assembled components to vacuum treatment at 600° C. for 3 h;

[0054] S40, placing the vacuum-treated component into pyrophyllite, and sintering at 4 GPa and 1500° C. to obtain the double-layer diamond composite material.

[0055] The structure of the obtained double-layer diamond composite material is as follows Figure 3 As shown, C1 is a thermally conductive metal and C2 is diamond powder.

[0056] Example 2

[0057] A method for preparing a sandwich diamond composite material comprises the steps of:

[0058] S10, providing diamond powder and thermally conductive metal powder coated with a thermally conductive metal film on the surface;

[0059] S20, placing a heat-conducting metal sheet into a niobium cup, mixing the diamond powder and the heat-conducting metal powder in a mass ratio of 99:1 and laying the mixture on the heat-conducting metal sheet, and then placing the heat-conducting metal sheet to obtain an assembled component;

[0060] S30, subjecting the assembled components to vacuum treatment at 600° C. for 3 h;

[0061] S40, placing the vacuum-treated components into pyrophyllite, and sintering at 4 GPa and 1500° C. to obtain the sandwich diamond composite material.

[0062] The structure of the obtained sandwich diamond composite material is as follows Figure 4 As shown, C1 is a thermally conductive metal and C2 is diamond powder.

[0063] Depend on Figure 3 and Figure 4 It can be seen that the thermally conductive metal powder with a smaller particle size is evenly coated around the diamond powder.

[0064] In order to understand the performance of the prepared diamond composite material, the present invention adopts a steady-state heat flow method to calibrate the thermal conductivity of the sample, wherein a 10*10*1 double-sided polished sample is placed between a hot plate and a cold plate for steady-state heat conduction, and finally the thermal conductivity of the required sample is obtained. Specifically, the diamond composite material prepared in Example 1 is tested three times, and the test results are shown in Table 1. It can be seen that the thermal conductivity of the diamond composite material prepared by the preparation method of the present invention is greatly improved.

[0065] Table 1

[0066]

[0067]

[0068] In summary, the present invention discloses a diamond composite material and a preparation method thereof, the method comprising the steps of: providing diamond powder and heat-conductive metal powder; mixing the diamond powder and the heat-conductive metal powder and spreading them in a metal cup, placing a heat-conductive metal sheet, and obtaining an assembled component; or placing a heat-conductive metal sheet in a metal cup, mixing the diamond powder and the heat-conductive metal powder and spreading them on the heat-conductive metal sheet, and then placing the heat-conductive metal sheet to obtain an assembled component; vacuum-treating the assembled component at a first preset temperature; placing the vacuum-treated component into a pyrophyllite synthesis component, and sintering it at a preset pressure and a second preset temperature to obtain the diamond composite material. The present invention prepares a diamond composite material by sintering diamond powder and heat-conducting metal powder together under high temperature and high pressure, so that the finally prepared diamond composite material can have the high hardness and high thermal conductivity of diamond and heat-conducting metal, and at the same time, the thermal expansion coefficient of the prepared diamond composite material can be adjusted by adjusting the content of diamond powder. The preparation method of the present invention has the advantages of simple preparation technology and strong repeatability of operation, and the prepared diamond composite material has excellent thermal conductivity, high density and good repeatability.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a diamond composite material, characterized in that: Includes steps: Provide diamond powder and thermal conductive metal powder; The diamond powder and the heat-conducting metal powder are mixed and spread on a metal cup, and a heat-conducting metal sheet is placed in the cup to obtain an assembled component; or, a heat-conducting metal sheet is placed in a metal cup, the diamond powder and the heat-conducting metal powder are mixed and spread on the heat-conducting metal sheet, and then the heat-conducting metal sheet is placed in the cup to obtain an assembled component; performing vacuum treatment on the assembled components at a first preset temperature; The vacuum-treated component is loaded into a pyrophyllite synthesis component, and sintered at a preset pressure and a second preset temperature to obtain the diamond composite material; The first preset temperature is 500-700° C., and the vacuum treatment time is 2-10 hours; The second preset temperature is 800-2000° C., and the preset pressure is 2-10 GPa; The diamond powder is diamond powder with a heat-conducting metal film coated on the surface; The heat-conductive metal powder is selected from one of copper powder, aluminum powder, silver powder, gold powder, copper alloy powder, aluminum alloy powder, and silver alloy powder, and the thermal conductivity of the heat-conductive metal powder is 200 to 550 W / mK; The heat-conducting metal sheet is selected from one of a copper sheet, an aluminum sheet, a silver sheet, a gold sheet, a copper alloy sheet, an aluminum alloy sheet, and a silver alloy sheet, and the thermal conductivity of the heat-conducting metal sheet is 200 to 550 W / mK; The diamond composite material is a double-layer structure or a sandwich structure; The heat-conductive metal film is one of a copper film, an aluminum film, a silver film, a gold film, a copper alloy film, an aluminum alloy film, and a silver alloy film, and the thermal conductivity of the heat-conductive metal film is 200 to 500 W / mK; The diamond powder and the heat-conducting metal powder are mixed in a weight ratio of 85-99.9:0.01-15, the particle size of the diamond powder is 10-500 μm, the particle size of the heat-conducting metal powder is 1-20 μm, and the thickness of the heat-conducting metal sheet is 0.5-5 mm; The metal cup is made of one or more of molybdenum, niobium, zirconium and tantalum.

2. A diamond composite material, characterized in that: The method according to claim 1 is used to prepare it.

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