Tablet hot-pressed diamond and its preparation auxiliary and manufacturing method

Abstract

The application provides a sheet-shaped hot-pressed diamond and a preparation auxiliary and a manufacturing method thereof, wherein the preparation auxiliary comprises a core column and a synthesis block; the core column comprises a metal cup, a heat insulation material layer arranged at the periphery of the metal cup, and an insulating material layer arranged at the upper and lower ends of the metal cup, and diamond micro-powder to be formed is filled between the two insulating material layers; the synthesis block comprises an inner lining layer and a protective layer, wherein the inner lining layer is wrapped at the periphery of the core column, and the protective layer is wrapped at the periphery of the inner lining layer. The sheet-shaped hot-pressed diamond and the preparation auxiliary and the manufacturing method thereof can solve the problem that the existing polycrystalline diamond compact as a CVD process substrate material has a catalyst or an adhesive in the interior, thereby affecting the CVD diamond generation quality.

Description

Technical Field

[0001] This invention relates to the field of synthetic diamond technology, and more specifically, to a sheet-like hot-pressed diamond, its preparation auxiliary components, and its manufacturing method. Background Technology

[0002] CVD diamond refers to polycrystalline diamond synthesized through the CVD (Chemical Vapor Deposition) process. In the process of synthesizing polycrystalline diamond using the CVD process, a substrate made of materials such as silicon or molybdenum is usually used, and then diamond crystals are generated on the substrate through a series of operations. However, due to the difference in the coefficient of thermal expansion between diamond and the substrate made of such materials, huge stress can be easily introduced, which can lead to cracking of the final CVD diamond.

[0003] To address the aforementioned technical problems, a novel substrate with a similar coefficient of thermal expansion to diamond is needed. For example, in existing technologies, polycrystalline diamond composite sheets sintered under high temperature and pressure have been used to fabricate substrates in CVD processes. These polycrystalline diamond composite sheets are mostly formed by sintering diamond micropowder with catalysts or binders under high temperature and pressure conditions (currently, cobalt is the most commonly used catalyst, and silicon carbide is the most commonly used binder). However, due to the presence of the catalyst (or binder) within the polycrystalline diamond composite sheet, there are differences in the physicochemical properties between the diamond and the catalyst, resulting in poor thermal stability. Therefore, during subsequent processing and operation of the polycrystalline diamond composite sheet (such as when used as a substrate in CVD processes), temperature changes can cause residual stress within the polycrystalline diamond composite sheet, thereby affecting the quality of CVD diamond formation.

[0004] Based on the above technical problems, there is an urgent need for a CVD process substrate material that does not contain catalysts or binders and has a thermal expansion coefficient close to that of diamond. Summary of the Invention

[0005] In view of the above problems, the purpose of this invention is to provide a sheet-like hot-pressed diamond, its preparation auxiliary parts and manufacturing method, so as to solve the problem that the quality of CVD diamond generation is affected by the presence of catalysts or binders inside the existing polycrystalline diamond composite sheets used as substrate materials for CVD processes.

[0006] The sheet-shaped hot-pressed diamond preparation auxiliary component provided by the present invention includes a core column and a composite block; wherein, the core column includes a metal cup, a heat-insulating material layer disposed around the metal cup, and an insulating material layer disposed at the upper and lower ends inside the metal cup, and the diamond micro powder to be formed is filled between the two insulating material layers;

[0007] The composite block includes an inner liner and a protective layer, wherein the inner liner wraps around the periphery of the core post, and the protective layer wraps around the periphery of the inner liner.

[0008] Furthermore, in a preferred embodiment, the composite block further includes a heating layer disposed within the core column, the heating layer being located between the heat insulation material layer and the metal cup.

[0009] Furthermore, a preferred embodiment is that the protective layer comprises a foliated paraffin layer surrounding the inner liner and a conductive metal block disposed on the foliated paraffin layer.

[0010] Furthermore, a preferred embodiment is that the metal cup is a niobium cup; and / or,

[0011] The material of the insulation layer includes at least one of zirconium oxide, magnesium oxide and samarium oxide; and / or, the inner lining is a dolomite inner lining.

[0012] On the other hand, the present invention also provides a method for preparing sheet-like hot-pressed diamond, wherein the preparation method utilizes the aforementioned sheet-like hot-pressed diamond preparation auxiliary components, and the preparation method includes:

[0013] The diamond micro powder is filled into the metal cup, and the insulating material layer is provided at the upper and lower ends of the metal cup, and the heat insulation material layer is provided on the outer periphery of the metal cup to form the core column;

[0014] The core post is assembled with the composite block to form an assembled block;

[0015] The assembled block is placed in a static high-pressure equipment for hot pressing.

[0016] After the hot pressing operation is completed, the assembly block is removed after cooling and depressurization.

[0017] Remove the sheet-like hot-pressed diamond preparation auxiliary parts from the assembly block to form sheet-like hot-pressed diamond.

[0018] Furthermore, a preferred embodiment is that the hot-pressing process for the assembly block includes:

[0019] First, pressurize the assembly block to a preset pressure range, then heat the assembly block to a preset temperature range, and then keep the assembly block at that temperature for a preset time.

[0020] Furthermore, in a preferred embodiment, the diamond micro powder has a particle size range of 0.01 μm to 200 μm; and the diamond micro powder includes at least one of small-particle-size diamond micro powder, medium-particle-size diamond micro powder, and large-particle-size diamond micro powder; wherein the small-particle-size diamond micro powder has a particle size range of 0.01 μm to 10 μm, the medium-particle-size diamond micro powder has a particle size range of 10 μm to 40 μm, and the large-particle-size diamond micro powder has a particle size range of 40 μm to 200 μm.

[0021] Furthermore, a preferred embodiment is that the process of removing the sheet-like hot-pressed diamond fabrication auxiliary parts from the assembly block includes:

[0022] The composite block, the heat insulation material layer, and the insulating material layer are removed by tapping, and the metal cup is removed by acid washing.

[0023] Finally, the present invention also provides a sheet-shaped hot-pressed diamond, which is manufactured using the aforementioned sheet-shaped hot-pressed diamond manufacturing method.

[0024] Furthermore, a preferred embodiment is that the thermal conductivity of the sheet-shaped hot-pressed diamond is ≥150W / (m·K), and the electrical resistance of the sheet-shaped hot-pressed diamond is ≥10Ω.

[0025] Compared with existing technologies, the sheet-like hot-pressed diamond, its preparation auxiliary components, and manufacturing method provided by this invention achieve the fabrication of sheet-like hot-pressed diamond through a hot-pressing process by setting auxiliary components such as core pillars and synthesis blocks. It utilizes the hot-pressing deformation of diamond to achieve a high-density, impurity-free polycrystalline diamond aggregate. Compared with polycrystalline diamond composite sheets produced by existing processes, it has advantages such as a low coefficient of thermal expansion, high thermal conductivity, good thermal stability, low cost, and lower stiffness, making it easier to remove later. Furthermore, it does not use catalysts or binders, and the process is simple and efficient. In addition, the sheet-like hot-pressed diamond provided by this invention has sufficient matrix strength and possesses the inherent coefficient of thermal expansion of diamond, providing a new substrate material option for the synthesis of polycrystalline diamond using CVD processes.

[0026] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below and particularly pointed out in the claims. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to include all such aspects and their equivalents. Attached Figure Description

[0027] Other objects and results of the invention will become more apparent and readily understood upon reference to the following description taken in conjunction with the accompanying drawings and the contents of the claims, and with a more complete understanding of the invention. In the drawings:

[0028] Figure 1 A schematic diagram of the assembly block used in synthesizing the sheet-like hot-pressed diamond provided by the present invention;

[0029] Figure 2 This is a scanning electron microscope image of the sheet-like hot-pressed diamond obtained in Example 1.

[0030] Figure 3 The image shows the Raman spectrum of the sheet-like hot-pressed diamond synthesized in Example 1.

[0031] Figure 4 This is an image of the sheet-like hot-pressed diamond obtained in Example 3.

[0032] Figure 5 Image of the sheet-like hot-pressed diamond obtained in Example 3;

[0033] Reference numerals: 1-Conductive metal block, 2-Inner lining layer, 3-Insulation material layer, 4-Metal cup, 5-Diamond micro powder, 6-Heating layer, 7-Insulation material layer, 8-Pyrophyllite layer.

[0034] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0035] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details. In other instances, well-known structures and devices are shown in block diagram form for ease of description of one or more embodiments.

[0036] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Figure 1 The structure of the assembly block used in the synthesis of sheet-like hot-pressed diamond provided by the present invention is shown, consisting of... Figure 1 It is understood that the sheet-like hot-pressed diamond preparation auxiliary component provided by the present invention includes a core column as a central support and a composite block as an outer protective body.

[0038] Specifically, the core column, as the central support, includes a metal cup 4 for containing the diamond micro powder 5 to be formed, a heat-insulating material layer 3 for insulating its interior, and an insulating layer for insulating its interior. The metal cup 4 is located at the center of the core column and has a cup-shaped structure with openings at the top and bottom. The heat-insulating material layer 3 is placed around the metal cup 4 (surrounding the metal cup 4 on all six sides) to ensure stable internal temperature. The diamond micro powder 5 to be formed is filled in the middle of the metal cup 4. The insulating material layer 7 is placed at the top and bottom ends inside the metal cup 4, with the diamond micro powder 5 between the two insulating material layers 7. The two insulating material layers 7 provide compression, positioning, and insulation protection for the diamond micro powder 5.

[0039] More specifically, to achieve the protective function of the synthetic block for the core, the synthetic block may include an inner liner 2 and a protective layer, wherein the inner liner 2 first wraps around the periphery of the core, and then the protective layer wraps around the periphery of the inner liner 2; further, the protective layer may include a foliated paraffin layer wrapped around the periphery of the inner liner 2 and a conductive metal block 1 disposed on the foliated paraffin layer, the conductive metal block 1 being used for electrical connection between the synthetic block and the outside.

[0040] It should be noted that, in order to heat the diamond micro powder 5, the composite block also needs to include a heating layer 6 disposed in the core column. The heating layer 6 needs to be located between the heat insulation material layer 3 and the metal cup 4, and is used to heat the metal cup 4 and the diamond micro powder 5 inside it.

[0041] In the actual material selection process, the metal cup 4 is usually a niobium cup; the material of the heat insulation layer 3 is usually at least one of the low thermal conductivity materials such as zirconium oxide, magnesium oxide and samarium oxide. In addition, the heat insulation layer 3 needs to be designed and combined according to the material and height to ensure the internal temperature stability; the inner lining layer 2 is usually a dolomite inner lining layer 2.

[0042] To further illustrate the method of using the sheet-like hot-pressed diamond preparation auxiliary component provided by the present invention, the present invention also provides a method for preparing sheet-like hot-pressed diamond. The preparation method utilizes the aforementioned sheet-like hot-pressed diamond preparation auxiliary component. Specifically, the preparation method includes:

[0043] Diamond micro powder 5 is filled into a metal cup 4, and insulating material layers 7 are provided at the upper and lower ends of the metal cup 4. A heat insulation material layer 3 is provided on the outer periphery of the metal cup 4 to form a core column; wherein, the core column includes a heat insulation material layer 3 provided on the outer layer, two insulating material layers 7 provided on the inner layer, and a metal cup 4 provided between the two insulating material layers 7.

[0044] The core pillar is assembled with a pre-designed composite block to form an assembled block (with a structure such as...). Figure 1 As shown, the composite block includes an inner liner 2 and a protective layer. The inner liner 2 is first wrapped around the periphery of the core column, and then the protective layer is wrapped around the periphery of the inner liner 2.

[0045] The assembled blocks are placed in a static high-pressure equipment for hot pressing.

[0046] After the hot pressing operation is completed, the assembled block is removed after cooling and depressurization (wherein, the preferred cooling rate during cooling is 1℃ / min~6000℃ / min, and the preferred depressurization rate during depressurization is ≤2GPa / min);

[0047] Remove the sheet-like hot-pressed diamond preparation auxiliary parts from the assembly block to form sheet-like hot-pressed diamond.

[0048] Specifically, the process of hot-pressing the assembly blocks includes:

[0049] First, pressurize the assembly block to a preset pressure range (e.g., ≥4 GPa, preferably 4 GPa to 10 GPa), with a pressurization rate preferably of 0.1 to 10 GPa / min; then heat the assembly block to a preset temperature range (e.g., ≥800℃, preferably 800℃ to 2000℃), with a heating rate preferably of 1℃ / min to 1000℃ / min; then hold the assembly block at this temperature for a preset time (e.g., ≥3 min).

[0050] It should be noted that the present invention relates to the hot pressing and sintering of diamond micropowder 5 into a certain shape using a high-temperature and high-pressure equipment (i.e., a static high-pressure equipment) to produce a novel material, referred to in this invention as sheet-like hot-pressed diamond. Furthermore, the properties of the sheet-like hot-pressed diamond can be altered by selecting different raw materials and controlling the processing parameters of the production process, resulting in sheet-like hot-pressed diamond with specific hardness, thermal conductivity, and electrical resistance. For example, regarding the raw materials, the diamond micropowder 5 selected in this invention comprises diamond micropowder with a particle size range of 0.01 μm to 200 μm; and the diamond micropowder 5 comprises at least one of small-particle-size diamond micropowder, medium-particle-size diamond micropowder, and large-particle-size diamond micropowder; wherein the small-particle-size diamond micropowder has a particle size range of 0.01 μm to 10 μm, the medium-particle-size diamond micropowder has a particle size range of 10 μm to 40 μm, and the large-particle-size diamond micropowder has a particle size range of 40 μm to 200 μm.

[0051] Furthermore, the device provided by this invention for achieving high temperature and high pressure for diamond micro powder 5 is a static high pressure device, such as the hinged six-sided top press manufactured by Zhengzhou No. 3 Grinding Mill.

[0052] Specifically, the process of removing the sheet-like hot-pressed diamond auxiliary parts from the assembly block includes: removing the composite block, the heat insulation material layer 3, and the insulating material layer 7 by hammering, and removing the metal cup 4 by acid washing; wherein, the above-mentioned acid washing method involves immersing the hammered block in an acid solution at 5℃~200℃ until the material of the metal cup 4 is completely detached, and the acid solution is at least one of nitric acid solution, hydrochloric acid solution, sulfuric acid solution, and hydrofluoric acid solution.

[0053] The method for preparing sheet-like hot-pressed diamond provided by the present invention will be further explained and illustrated below with specific embodiments.

[0054] Example 1

[0055] In this embodiment, the diamond micro powder 5 has a large particle size, a purity of 99.99%, and a weight of 2.0g. Specifically, the steps for synthesizing sheet-like hot-pressed diamond under high temperature and high pressure are as follows:

[0056] (1) Diamond micro powder 5 is filled into a metal cup 4, and insulating material layers 7 are provided at the upper and lower ends of the metal cup 4, and heat insulation material layer 3 is provided on the periphery of the metal cup 4 to form a core column; wherein, the core column includes insulating material layers 7 (e.g., sodium chloride layer) at the upper and lower ends and heat insulation material layer 3 (zirconia layer) on the periphery, and a metal cup 44 between the two insulating material layers 7. The core column and the composite block are assembled to obtain an assembly block, wherein the composite block includes a pyrophyllite layer, a heating layer 6, a dolomite liner and a conductive metal block 1.

[0057] (2) Place the assembly block into a static high pressure equipment (hinged six-sided press), pressurize it to 5GPa at a pressurization rate of 7GPa / h, and then heat it to 1500℃ at a heating rate of 100℃ / min. Hold the temperature and pressure for ≥5min under the above pressure and temperature to sinter the diamond micro powder 5.

[0058] (3) After the heat preservation and pressure sintering is completed, the temperature and pressure are reduced to room temperature and pressure at a cooling rate of 300℃ / min and a pressure reduction rate of 10GPa / h. Then, the six-sided top press is returned and the sample (i.e. the sintered assembly block) is taken out. The sample surface is removed by knocking, and the insulating material layer 7, the heat insulation material layer 3 and the composite block material are removed. The remaining sample is then placed in a 1:3 mixed solution of concentrated nitric acid and hydrofluoric acid to remove the catalyst (remove the material of the metal cup 4). The sample is then further ultrasonically cleaned with deionized water to remove residual acid and dried to remove surface moisture, resulting in sheet-like hot-pressed diamond.

[0059] The SEM image of the sheet-like hot-pressed diamond prepared in this embodiment is shown below. Figure 2 As shown, the diamond particles are tightly sintered, with smaller, broken diamond particles surrounding the larger ones; its Raman spectrum is shown below. Figure 3 As shown, Raman spectroscopy detected a diamond characteristic peak at 1332 cm⁻¹. -1 This indicates that the product prepared is still diamond.

[0060] Example 2

[0061] In this embodiment, the diamond micro powder with a particle size of 5 is a mixture of small-particle-size diamond micro powder and large-particle-size diamond micro powder, wherein the ratio is 1:3, the purity is 99.99%, and the weight is 2.0g; specifically, the steps for synthesizing sheet-like hot-pressed diamond under high temperature and high pressure are as follows:

[0062] (1) Diamond micro powder 5 is filled into a metal cup 4, and insulating material layers 7 are provided at the upper and lower ends of the metal cup 4, and heat insulation material layer 3 is provided on the periphery of the metal cup 4 to form a core column; wherein, the core column includes insulating material layers 7 (e.g., sodium chloride layer) at the upper and lower ends and heat insulation material layer 3 (zirconia layer) on the periphery, and a metal cup 44 between the two insulating material layers 7. The core column and the composite block are assembled to obtain an assembly block, wherein the composite block includes a pyrophyllite layer, a heating layer 6, a dolomite liner and a conductive metal block 1.

[0063] (2) Place the assembly block into a static high pressure equipment (hinged six-sided press), pressurize it to 5GPa at a pressurization rate of 7GPa / h, and then heat it to 1500℃ at a heating rate of 100℃ / min. Hold the temperature and pressure for ≥5min under the above pressure and temperature to sinter the diamond micro powder 5.

[0064] (3) After the heat preservation and pressure sintering is completed, the temperature and pressure are reduced to room temperature and pressure at a cooling rate of 300℃ / min and a pressure reduction rate of 10GPa / h. Then, the six-sided top press is returned and the sample (i.e. the sintered assembly block) is taken out. The sample surface is removed by knocking, and the insulating material layer 7, the heat insulation material layer 3 and the composite block material are removed. The remaining sample is then placed in a 1:3 mixed solution of concentrated nitric acid and hydrofluoric acid to remove the catalyst (remove the material of the metal cup 4). The sample is then further ultrasonically cleaned with deionized water to remove residual acid and dried to remove surface moisture, resulting in sheet-like hot-pressed diamond.

[0065] Example 3

[0066] In this embodiment, the diamond micro powder 5 is a mixture of small-particle-size, medium-particle-size, and large-particle-size diamond micro powders, with a purity of 99.99% and a weight of 2.0g. Specifically, the steps for synthesizing sheet-like hot-pressed diamond under high temperature and high pressure are as follows:

[0067] (1) Diamond micro powder 5 is filled into a metal cup 4, and insulating material layers 7 are provided at the upper and lower ends of the metal cup 4, and heat insulation material layer 3 is provided on the periphery of the metal cup 4 to form a core column; wherein, the core column includes insulating material layers 7 (e.g., sodium chloride layer) at the upper and lower ends and heat insulation material layer 3 (zirconia layer) on the periphery, and a metal cup 44 between the two insulating material layers 7. The core column and the composite block are assembled to obtain an assembly block, wherein the composite block includes a pyrophyllite layer, a heating layer 6, a dolomite liner and a conductive metal block 1.

[0068] (2) Place the assembly block into a static high pressure equipment (hinged six-sided press), pressurize it to 5GPa at a pressurization rate of 7GPa / h, and then heat it to 1500℃ at a heating rate of 100℃ / min. Hold the temperature and pressure for ≥5min under the above pressure and temperature to sinter the diamond micro powder 5.

[0069] (3) After the heat preservation and pressure sintering is completed, the temperature and pressure are reduced to room temperature and pressure at a cooling rate of 300℃ / min and a pressure reduction rate of 10GPa / h. Then, the six-sided top press is returned and the sample (i.e. the sintered assembly block) is taken out. The sample surface is removed by knocking, and the insulating material layer 7, the heat insulation material layer 3 and the composite block material are removed. The remaining sample is then placed in a 1:3 mixed solution of concentrated nitric acid and hydrofluoric acid to remove the catalyst (remove the material of the metal cup 4). The sample is then further ultrasonically cleaned with deionized water to remove residual acid and dried to remove surface moisture, resulting in sheet-like hot-pressed diamond.

[0070] The optical micrograph of the sheet-like hot-pressed diamond synthesized in this embodiment is as follows: Figure 4 , Figure 5 As shown in the two figures, the sheet-like hot-pressed diamond has a diameter of approximately 14 mm and a thickness of approximately 3 mm.

[0071] Finally, it should be noted that the present invention also provides a sheet-shaped hot-pressed diamond, which is made based on the aforementioned sheet-shaped hot-pressed diamond fabrication auxiliary parts using the aforementioned sheet-shaped hot-pressed diamond fabrication method. The sheet-shaped hot-pressed diamond produced by the present invention typically has a diameter ≥14mm, a thermal conductivity ≥150W / (m·K), and a resistance ≥10Ω.

[0072] As can be seen from the above specific embodiments, the sheet-like hot-pressed diamond, its preparation auxiliary parts, and manufacturing method provided by the present invention have at least the following advantages:

[0073] 1. The solution provided by the present invention synthesizes sheet-like hot-pressed diamond by high temperature and high pressure without using catalysts and binders. Since there are no catalysts and binders inside, the sheet-like hot-pressed diamond has strong stability and can be used to make CVD process substrates.

[0074] 2. The solution provided by this invention utilizes diamond hot-pressing deformation to achieve the fabrication of high-density, impurity-free diamond polycrystalline aggregates (i.e., sheet-like hot-pressed diamond). The resulting sheet-like hot-pressed diamond has advantages such as low coefficient of thermal expansion, high thermal conductivity, good thermal stability, low cost, and low stiffness, making it easy to remove later.

[0075] 3. The sheet-shaped hot-pressed diamond obtained by this invention has a diameter ≥14mm, a thermal conductivity ≥150W / (m·K), and a resistance ≥10Ω. By selecting different raw materials and controlling the processing parameters of the production process, the resistance and thermal conductivity of the sheet-shaped hot-pressed diamond can be changed.

[0076] 4. The sheet-like hot-pressed diamond prepared by this invention has sufficient matrix strength and the thermal expansion coefficient of diamond itself, which can provide a new matrix option for CVD synthesis of polycrystalline diamond and has unique potential applications in electrode materials and CVD substrate materials.

[0077] As referred above Figures 1 to 5 The sheet-like hot-pressed diamond, its preparation aids, and manufacturing method according to the present invention are described by way of example. However, those skilled in the art will understand that various modifications can be made to the sheet-like hot-pressed diamond, its preparation aids, and manufacturing method proposed in the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the content of the appended claims.

Claims

1. A method for preparing sheet-like hot-pressed diamond, characterized in that, The preparation method utilizes a sheet-like hot-pressed diamond preparation auxiliary component, which includes a core and a composite block. The core includes a metal cup, a heat-insulating material layer disposed around the metal cup, and an insulating material layer disposed at the upper and lower ends inside the metal cup. The diamond micro powder to be formed is filled between the two insulating material layers. The composite block includes an inner liner and a protective layer, wherein the inner liner wraps around the periphery of the core post, and the protective layer wraps around the periphery of the inner liner; The composite block further includes a heating layer disposed within the core column, the heating layer being located between the heat insulation material layer and the metal cup; the method for preparing the sheet-like hot-pressed diamond includes: The diamond micro powder is filled into the metal cup without using a catalyst or binder, and the insulating material layer is provided at the upper and lower ends of the metal cup, and the heat insulation material layer is provided on the outer periphery of the metal cup to form the core column; The core post is assembled with the composite block to form an assembled block; The assembled block is placed in a static high-pressure equipment for hot pressing. After the hot pressing operation is completed, the assembly block is removed after cooling and depressurization. Remove the sheet-like hot-pressed diamond preparation auxiliary parts from the assembly block to form sheet-like hot-pressed diamond; wherein, The process of hot-pressing the assembly block includes: First, pressurize the assembly block to a preset pressure range of 4 GPa to 10 GPa, then heat the assembly block to a preset temperature range of 800 ℃ to 2000 ℃, and then keep the assembly block at that temperature for a preset time. The diamond micropowder has a particle size ranging from 0.01 μm to 200 μm; and, The diamond micro powder includes at least one of small-particle-size diamond micro powder, medium-particle-size diamond micro powder, and large-particle-size diamond micro powder; wherein the particle size range of the small-particle-size diamond micro powder is 0.01 μm to 10 μm, the particle size range of the medium-particle-size diamond micro powder is 10 μm to 40 μm, and the particle size range of the large-particle-size diamond micro powder is 40 μm to 200 μm.

2. The method for preparing sheet-like hot-pressed diamond as described in claim 1, characterized in that, The protective layer includes a leaf wax layer surrounding the inner liner and a conductive metal block disposed on the leaf wax layer.

3. The method for preparing sheet-like hot-pressed diamond as described in claim 1, characterized in that, The metal cup is a niobium cup; and / or, The material of the thermal insulation layer includes at least one of zirconium oxide, magnesium oxide, and samarium oxide; and / or, The inner lining is a dolomite inner lining.

4. The method for preparing sheet-like hot-pressed diamond as described in claim 1, characterized in that, The process of removing the sheet-like hot-pressed diamond fabrication auxiliary parts from the assembly block includes: The composite block, the heat insulation material layer, and the insulating material layer are removed by tapping, and the metal cup is removed by acid washing.

5. A sheet-like hot-pressed diamond, characterized in that, The sheet-shaped hot-pressed diamond is manufactured using the sheet-shaped hot-pressed diamond manufacturing method according to any one of claims 1 to 4.

6. The sheet-like hot-pressed diamond as described in claim 5, characterized in that, The thermal conductivity of the sheet-shaped hot-pressed diamond is ≥150 W / (m·K), and the electrical resistance of the sheet-shaped hot-pressed diamond is ≥10Ω.

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