High-thermal-conductivity diamond-based heat dissipation material with ordered arrangement and preparation method thereof

Abstract

The application discloses an ordered arrangement high-thermal-conductivity diamond-based heat dissipation material and a preparation method thereof, relates to the technical field of diamond heat dissipation materials, and comprises the following steps: polishing diamond to obtain a diamond reinforcement; using a cross-suiting method to pack the diamond reinforcement into a metal cup to obtain a sealed suit; performing vacuum treatment on the sealed suit; packing the suit after the vacuum treatment into a synthetic block; performing ultrahigh-pressure sintering on the synthetic block to obtain a sample blank; and performing mechanical processing on the sample blank to obtain a diamond-based heat dissipation material with a required size. The application can arrange the diamond and the Cu-based metal in an ordered manner, improves the volume fraction of the diamond in the heat dissipation material, adds a carbide generating element in the copper to optimize the affinity of the copper and the diamond interface, improves the thermal conductivity of the diamond / Cu composite material, and overcomes the poor heat conduction performance of the electronic packaging material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of diamond heat dissipation materials, and more particularly to an orderly arranged high-thermal-conductivity diamond-based heat dissipation material and a preparation method thereof. BACKGROUND

[0002] Diamond has excellent thermal conductivity and low thermal expansion coefficient, and is widely used in electronic devices, aerospace, semiconductors and other fields, and is also used in the field of electronic packaging materials, which can quickly and effectively conduct the heat generated by electronic devices during operation, reduce the formation of hot spots, and thus improve the stability and life of the device. However, due to the limitations of diamond growth process, the size of single diamond is small and cannot be directly used for high-power device heat dissipation, so it is combined with high-thermal-conductivity metal materials such as copper to form a diamond-based heat dissipation material to expand the application range.

[0003] In the preparation process of the current diamond / Cu composite material, the following problems still exist:

[0004] 1. During the preparation process, the diamond particles in different regions are compressed or sintered to different degrees, resulting in different sizes. When the sintering pressure is insufficient, the particles are loosely combined, and large particles are not fully crushed, while in the high-pressure region, smaller particles are formed due to excessive compression, causing significant size differences in the diamond particles in the diamond / Cu composite material, which affects the thermal conductivity of the diamond / Cu composite material.

[0005] 2. The wettability of diamond and copper is very poor. When the volume fraction of diamond exceeds 60%, the copper matrix cannot completely fill the interstitial gaps between the particles through the infiltration process, forming pore defects, which causes a sharp decrease in the mechanical properties of the material. Therefore, the diamond content is usually controlled below 50%, which reduces the diamond content in the diamond / Cu composite material and affects the overall thermal conductivity.

[0006] 3. When no effective surface treatment is performed, the interface between diamond and copper is poorly combined, and there is a nanoscale gap between diamond and the copper matrix, which prevents the copper from uniformly coating the particles during hot pressing, forming a defect structure in which "copper-rich regions" and "diamond-rich regions" are alternately distributed, which prevents the formation of a continuous thermal conduction path and results in poor heat dissipation. At the same time, the high proportion of copper matrix in local areas can cause the thermal expansion coefficient of the material to deviate from the design value.

[0007] These characteristics affect the heat dissipation effect and thermal expansion coefficient of the diamond / Cu composite material. Therefore, the present application provides an orderly arranged high-thermal-conductivity diamond-based heat dissipation material and a preparation method thereof to solve the above problems of the prior art. SUMMARY

[0008] The application aims at solving the problems in the background art.

[0009] In order to achieve the above-mentioned purpose, the application specifically adopts the following technical scheme:

[0010] The application discloses an ordered high-thermal-conductivity diamond-based heat dissipation material and a preparation method thereof.

[0011] The application discloses an ordered high-thermal-conductivity diamond-based heat dissipation material and a preparation method thereof.

[0012] S1, diamond pretreatment: polishing diamond single crystals to obtain diamond reinforcement in a cuboid structure;

[0013] S2, mold loading: laying the diamond reinforcement in a metal large cup, covering Cu-based metal sheets on the diamond reinforcement, and finally covering a metal middle cup on the former to obtain a sealed package;

[0014] S3, vacuum treatment: vacuum treating the sealed package;

[0015] S4, synthesis block assembly: placing the vacuum-treated sealed package in a synthesis block for high temperature and high pressure;

[0016] S5, ultra-high pressure sintering: placing the synthesis block into a cavity of a six-surface pressing machine for ultra-high pressure sintering to obtain a sample blank;

[0017] S6, mechanical processing: processing the sample blank, cutting and grinding after removing the metal outer skin, and then obtaining a finished diamond / Cu composite material.

[0018] Preferably, the diamond reinforcement in the step S1 is in a cuboid structure, and the size is 0.1-5mm in length, 0.1-5mm in width and 0.1-5mm in height, and each surface of the diamond single crystal sheet is square (with {100} orientation).

[0019] Preferably, the Cu-based metal sheet in the step S2 contains one or both of Zr and B, and the content of the elements is 0-1.0wt.%.

[0020] Preferably, the temperature of the vacuum treatment in the step S3 is 500-600℃, and the treatment time is 1-2h.

[0021] Preferably, the synthesis block in the step S4 is composed of an electrically conductive steel ring, a pyrophyllite, a sodium chloride tube, a pressure transmission sheet and an insulating sheet.

[0022] Preferably, the ultra-high pressure sintering process in the step S6 is a process of first pressurizing and then heating, first cooling and then unloading pressure, the sintering temperature is 1000-1400℃, the pressure is 3-5GPa, and the holding time is 5-10min.

[0023] Preferably, the metal large cup and the metal middle cup used in the step S2 are molybdenum cups.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] By selecting single crystal diamond with {100} orientation, and by polishing and orderly arranging in the molybdenum cup, not only the interfacial bonding force between the diamond and the copper-based material can be increased, but also the orientation of the crystal can be realized, the pressure and temperature distribution can be effectively controlled, the internal structure of the material can be ensured to be more dense and uniform, the porosity and other defects can be reduced, and the thermal conductivity performance can be improved; the carbide added in the Cu matrix can carbonize the diamond surface, introduce an interfacial carbide layer, and the interfacial carbide layer can bridge the acoustic performance mismatch between Cu and diamond, thereby providing a fast channel for heat transfer, further improving the overall thermal conductivity, and at the same time, the high temperature and high pressure environment can make the molten Cu-based metal sheet fully fill around the reticular structure of the diamond, cooperate with the neatly arranged diamond, avoid the copper enrichment area, not only reduce the contact resistance between the metal and the diamond, but also enhance the mechanical bonding strength between the two, which is beneficial to the effective heat transfer. In summary, the thermal conductivity of the diamond / Cu heat dissipation material is improved, the thermal conductivity performance is improved to 960W / (m·K), which can be used for efficient heat dissipation of high-power devices, and the purpose of prolonging the service life of electronic devices is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The flowchart of the present application is shown in the figure;

[0027] Figure 2 The schematic diagram of the assembled structure of the synthesized block in the present application is shown in the figure. DETAILED DESCRIPTION

[0028] The present application is further described below in combination with the drawings of the specification and specific preferred embodiments, but the protection scope of the present application is not limited thereby.

[0029] The materials and instruments used in the following examples are all commercially available, among which the diamond single crystal is MD100 diamond single crystal (Henna Leading Innovation Material Technology Co., Ltd.), the single crystal sheet is square (with {100} orientation), and the specification is M8.

[0030] Example 1:

[0031] An orderly arranged high-thermal-conductivity diamond-based heat dissipation material, each side length of the diamond crystal ranges from 3 mm, i.e. a diamond with a cuboid structure of 3 mm in length, 3 mm in width and 3 mm in height, a Cu-based metal sheet used in the production steps is a metal sheet, which can penetrate into the gaps between the diamonds during the high-temperature and high-pressure process, and will be polished off after preparation.

[0032] A preparation method of an orderly arranged high-thermal-conductivity diamond-based heat dissipation material, comprising the following steps:

[0033] S1, diamond pretreatment: polishing a diamond single crystal to obtain a diamond reinforcement with a cuboid structure of 3 mm in length, 3 mm in width and 3 mm in height, each face of the diamond single crystal sheet being square (with {100} orientation);

[0034] S2, mold loading: laying the diamond reinforcement in a metal large cup, covering the diamond reinforcement with a Cu-based metal sheet, and finally covering the former with a metal middle cup to obtain a sealed package, wherein the Cu-based metal sheet contains 0.4wt.% of B;

[0035] S3, vacuum treatment: vacuum treatment of the sealed package, the temperature of the vacuum treatment being 550℃ and the treatment time being 1.5h;

[0036] S4, assembly of synthesis block: placing the sealed package after the vacuum treatment in a synthesis block for high-temperature and high-pressure, the structure of the synthesis block being as shown in Figure 2 , wherein the structure is composed of a conductive steel ring 201, a pyrophyllite 202, a graphite tube 203, a sodium chloride tube 204, an insulating cup 205, a pressure transmission sheet 206, a Cu-based metal sheet 207, a diamond reinforcement 208 and a titanium sheet 209;

[0037] S5, ultra-high pressure sintering: placing the synthesis block in a cavity of a six-surface press for ultra-high pressure sintering, adopting the procedure of first pressurizing and then heating, first cooling and then unloading pressure during the sintering process, setting the sintering temperature to be 1400℃, the pressure to be 4.6GPa and the holding time to be 7min to obtain a sample blank;

[0038] S6, mechanical processing: processing the sample blank, cutting and grinding after removing the metal skin, and then grinding with diamond abrasive during the processing to obtain a finished diamond / Cu composite material.

[0039] Example 2:

[0040] An orderly arranged high-thermal-conductivity diamond-based heat dissipation material, each side length of the diamond crystal ranges from 2 mm, i.e. a diamond with a cuboid structure of 2 mm in length, 2 mm in width and 2 mm in height.

[0041] A preparation method of an orderly arranged high-thermal-conductivity diamond-based heat dissipation material, comprising the following steps:

[0042] S1, diamond pretreatment: the diamond single crystal is polished to obtain a diamond reinforcement body with a size of 2 mm long, 2 mm wide, and 2 mm high rectangular structure, and each surface of the diamond single crystal wafer is square (with {100} orientation);

[0043] S2, mold loading: the diamond reinforcement body is laid flat in a metal large cup, a Cu-based metal sheet is covered on the diamond reinforcement body, and finally a metal middle cup is used to cover the former to obtain a sealed package, wherein the Cu-based metal sheet contains 0.3wt.% of B;

[0044] S3, vacuum treatment: the sealed package is subjected to vacuum treatment, and the vacuum treatment temperature is 570℃ and the treatment time is 2h;

[0045] S4, assembly of synthesis block: the sealed package after vacuum treatment is placed in a synthesis block for high temperature and high pressure, and the structure of the synthesis block is referred to Figure 2 ;

[0046] S5, ultra-high pressure sintering: the synthesis block is placed in the cavity of a six-sided top press for ultra-high pressure sintering, and during the sintering process, the procedure of first pressurizing and then heating, first cooling and then unloading is adopted, the sintering temperature is set to 1300℃, the pressure is 4.5GPa, and the holding time is 10min, to obtain a sample blank;

[0047] S6, mechanical processing: the sample blank is processed, the metal skin is removed, cutting and grinding are performed, diamond abrasive is used for grinding during the processing, and then a finished diamond / Cu composite material is obtained.

[0048] Example 3:

[0049] An orderly arranged high-thermal-conductivity diamond-based heat dissipation material, each side length of the diamond crystal ranges from 1mm, i.e. a rectangular structure of diamond with a length of 1mm, a width of 1mm, and a height of 1mm.

[0050] A method for preparing an orderly arranged high-thermal-conductivity diamond-based heat dissipation material, comprising the following steps:

[0051] S1, diamond pretreatment: the diamond single crystal is polished to obtain a diamond reinforcement body with a size of 1mm long, 1mm wide, and 1mm high rectangular structure, and each surface of the diamond single crystal wafer is square (with {100} orientation);

[0052] S2, mold loading: the diamond reinforcement body is laid flat in a metal large cup, a Cu-based metal sheet is covered on the diamond reinforcement body, and finally a metal middle cup is used to cover the former to obtain a sealed package, wherein the Cu-based metal sheet contains 1.0wt.% of Zr;

[0053] S3, vacuum treatment: vacuum treatment is performed on the sealed package, the temperature of the vacuum treatment is 550℃, and the treatment time is 2h;

[0054] S4, synthesis block assembly: the sealed package after the above vacuum treatment is placed in a synthesis block for high temperature and high pressure, the structure of the synthesis block is referred to Figure 2 ;

[0055] S5, ultra-high pressure sintering: the synthesis block is placed in a six-sided top press cavity for ultra-high pressure sintering, a procedure of first pressurizing and then heating, first cooling and then unloading pressure is adopted during the sintering process, the sintering temperature is set to 1200℃, the pressure is 3.5GPa, and the holding time is 6min, to obtain a sample blank;

[0056] S6, mechanical processing: the sample blank is processed, after the metal skin is removed, cutting and grinding are performed, diamond abrasive is used for grinding during the processing, and then a finished diamond / Cu composite material is obtained.

[0057] Comparative Example 1:

[0058] An orderly arranged high-thermal-conductivity diamond-based heat dissipation material, each side length of the diamond crystal ranges from 3mm, i.e. a diamond with a cuboid structure of 3mm in length, 3mm in width and 3mm in height.

[0059] A preparation method of an orderly arranged high-thermal-conductivity diamond-based heat dissipation material, comprising the following steps:

[0060] S1, diamond pretreatment: a diamond single crystal is polished to obtain a diamond reinforcement with a cuboid structure of 3mm in length, 3mm in width and 3mm in height, each surface of the diamond single crystal wafer is square (with {100} orientation);

[0061] S2, mold loading: the diamond reinforcement is laid flat in a metal large cup, a Cu-based metal sheet is covered on the diamond reinforcement, and finally a metal middle cup is used to cover the former to obtain a sealed package, wherein the Cu-based metal sheet contains 0.4wt.% of B;

[0062] S3, vacuum treatment: vacuum treatment is performed on the sealed package, the temperature of the vacuum treatment is room temperature, and the treatment time is 1.5h;

[0063] The remaining steps remain the same as those of Example 1.

[0064] The difference between Comparative Example 1 and Example 1 is that the temperature during vacuum treatment is changed to room temperature, and the remaining steps remain unchanged.

[0065] Comparative Example 2:

[0066] An orderly arranged high-thermal-conductivity diamond-based heat dissipation material, wherein each side length of the diamond crystal ranges from 2 mm, i.e., the diamond is in a cuboid structure with a length of 2 mm, a width of 2 mm and a height of 2 mm.

[0067] A preparation method of an orderly arranged high-thermal-conductivity diamond-based heat dissipation material, comprising the following steps:

[0068] S1, diamond pretreatment: polishing a diamond single crystal to obtain a diamond reinforcement in a cuboid structure with a length of 2 mm, a width of 2 mm and a height of 2 mm, wherein each face of the diamond single crystal is square (with {100} orientation);

[0069] S2, mold loading: laying the diamond reinforcement in a metal large cup, covering a Cu-based metal sheet on the diamond reinforcement, and finally covering a metal middle cup on the former to obtain a sealed package, wherein the Cu-based metal sheet contains 1.0 wt.% of B;

[0070] The remaining steps remain unchanged from those of Example 2.

[0071] Comparative Example 2 differs from Example 2 in that the content of B in the Cu-based metal sheet is changed, and the remaining steps remain unchanged.

[0072] Comparative Example 3:

[0073] An orderly arranged high-thermal-conductivity diamond-based heat dissipation material, wherein each side length of the diamond crystal ranges from 1 mm, i.e., the diamond is in a cuboid structure with a length of 1 mm, a width of 1 mm and a height of 1 mm.

[0074] A preparation method of a heat dissipation material, comprising the following steps:

[0075] S1, mold loading: pouring untreated diamond single crystals into a metal large cup, covering a Cu-based metal sheet on the diamond reinforcement, and finally covering a metal middle cup on the former to obtain a sealed package, wherein the Cu-based metal sheet contains 1.0 wt.% of Zr, and each face of the diamond single crystal is square (with {100} orientation);

[0076] S2, vacuum treatment: vacuum treating the sealed package, wherein the vacuum treatment temperature is 550°C and the treatment time is 2 h;

[0077] The remaining steps remain unchanged from those of Example 3.

[0078] Comparative Example 3 differs from Example 3 in that the diamond in Comparative Example 3 is not polished and is arranged in a scattered manner in the metal large cup.

[0079] The following compares and analyzes the thermal conductivity, diamond volume fraction and thermal expansion coefficient of Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2 and Comparative Example 3, and compares them with pure copper.

[0080] Table 1 Performance comparison table

[0081]

[0082] From the above table, the thermal conductivity of the diamond / Cu composite material obtained by examples 1-3 is higher than 960 W / (m·K), which has excellent thermal conductivity. At the same time, the thermal expansion efficiency is low, which can be widely applied to the packaging of electronic devices to improve its heat dissipation performance. Among them, the performance of example 1 is better than that of other examples. By comparing the data of example 1 and comparative example 1, it can be known that increasing the temperature during the vacuum treatment of the sealing package can improve the thermal conductivity of the finished product and reduce the thermal expansion coefficient; from example 2 and comparative example 2, it can be known that the addition amount of B is 0.3wt.% which is better than 1.0wt.%, and the formation of too much carbonized layer will cause the reduction of thermal conductivity; from example 3 and comparative example 3, it can be known that the regularly arranged diamond can improve the arrangement of diamond and copper-based metal in the finished product, avoid the copper enrichment area, and thus improve the overall thermal conductivity. When the vacuum is extracted, the copper-based metal will wrap the regularly arranged diamond tightly to avoid the uneven structure.

[0083] The preparation method of the diamond / Cu composite material of the present application realizes the significant improvement of the thermal conductivity effect of the diamond / Cu composite material by selecting diamond single crystal with {100} orientation, controlling the element ratio in the Cu-based metal sheet and the process conditions of superhigh pressure infiltration. The thermal conductivity of the diamond / Cu composite material and the volume ratio of diamond in the composite material are increased, the heat dissipation level of the electronic packaging tool is improved, and the service life of the electronic components is prolonged. Compared with the traditional preparation technology of diamond / Cu composite material, the method effectively improves the surface wettability of diamond and Cu, reduces the interface thermal resistance, and has high success rate, which provides a new idea for the diamond / Cu composite material.

[0084] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with a preferred embodiment, it is not intended to limit the present application. Any skilled person in the art can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments with equivalent changes, without departing from the spirit and technical solutions of the present application. Therefore, any simple modification, equivalent replacement, equivalent change and modification of the above embodiments made according to the technical essence of the present application, all within the scope of protection of the technical solutions of the present application.

Claims

1. A diamond-based heat dissipation material with ordered arrangement of high thermal conductivity, characterized in that, The diamond-based heat dissipation material is composed of diamond crystals arranged in an orderly manner, with the diamond crystals connected by a copper-based metal. The side length of each diamond crystal ranges from 0.1 to 5 mm. The ordered, highly thermally conductive diamond-based heat dissipation material is prepared by a method comprising the following production steps: S1. Diamond pretreatment: The diamond single crystal is polished to obtain a cube-shaped diamond reinforcement. S2. Molding: The diamond reinforcement is laid flat in the large metal cup, the Cu-based metal sheet is covered on the diamond reinforcement, and finally the middle metal cup is used to cover the former to obtain a sealed set. S3. Vacuum treatment: Vacuum treatment of the sealing package; S4. Assemble the composite block: Place the vacuum-treated sealed package into the composite block subjected to high temperature and high pressure. S5. Ultra-high pressure sintering: The above-mentioned composite block is placed into the cavity of a six-sided top press for ultra-high pressure sintering to obtain a sample blank. S6. Machining: The sample blank is processed by removing the metal outer skin, then cutting and grinding to obtain the finished diamond / Cu composite material. The Cu-based metal sheet in step S2 contains Zr or B, with Zr content ranging from 0-1.0 wt.% and B content ranging from 0-0.4 wt.%. The vacuum treatment in step S3 is performed at a temperature of 500-600℃ for 1-2 hours.

2. A method for preparing an ordered arrangement of high thermal conductivity diamond-based heat dissipation material, used to produce the ordered arrangement of high thermal conductivity diamond-based heat dissipation material of claim 1, characterized in that, Includes the following steps: S1. Diamond pretreatment: The diamond single crystal is polished to obtain a cube-shaped diamond reinforcement. S2. Molding: The diamond reinforcement is laid flat in the large metal cup, the Cu-based metal sheet is covered on the diamond reinforcement, and finally the middle metal cup is used to cover the former to obtain a sealed set. S3. Vacuum treatment: Vacuum treatment of the sealing package; S4. Assemble the composite block: Place the vacuum-treated sealed package into the composite block subjected to high temperature and high pressure. S5. Ultra-high pressure sintering: The above-mentioned composite block is placed in the cavity of a six-sided top press for ultra-high pressure sintering to obtain a sample blank. S6. Machining: The sample blank is processed by removing the metal outer skin, then cutting and grinding to obtain the finished diamond / Cu composite material. The Cu-based metal sheet in step S2 contains Zr or B, with Zr content ranging from 0-1.0 wt.% and B content ranging from 0-0.4 wt.%. The vacuum treatment in step S3 is performed at a temperature of 500-600℃ for 1-2 hours.

3. The method for preparing an ordered arrangement of high thermal conductivity diamond-based heat dissipation material according to claim 2, characterized in that, The diamond reinforcement in step S1 has a cubic structure with dimensions of length 0.1-5 mm, width 0.1-5 mm, and height 0.1-5 mm. Each face of the diamond single crystal wafer is square and has a {100} orientation.

4. The method for preparing an ordered arrangement of high thermal conductivity diamond-based heat dissipation material according to claim 2, characterized in that, The composite block in step S4 consists of a conductive steel ring, pyrophyllite, sodium chloride tube, pressure transfer sheet, and insulating sheet.

5. The method for preparing an ordered arrangement of high thermal conductivity diamond-based heat dissipation material according to claim 2, characterized in that, The ultra-high pressure sintering process in step S5 is a process of first pressurizing and then heating, then cooling and then depressurizing. The sintering temperature is 1000-1400℃, the pressure is 3-5GPa, and the holding time is 5-10min.

6. The method for preparing an ordered arrangement of high thermal conductivity diamond-based heat dissipation material according to claim 2, characterized in that, The large and medium metal cups used in step S2 are molybdenum cups.

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