Bonding type diamond cooling fin and preparation method thereof

Abstract

The invention belongs to the technical field of diamond radiating materials, and particularly discloses a bonding type diamond radiating fin and a preparation method thereof.The bonding type diamond radiating fin is prepared by the steps that a synthetic block is loaded into a cubic press, a segmented boosting technology is adopted for machining, silicon powder and silicon carbide micro powder in each layer are melted, single crystal diamond in the layers is bonded, and the bonding type diamond radiating fin is obtained; the silicon powder reacts with carbon atoms on the surface of the diamond single crystal to generate silicon carbide, the silicon micro-powder has the effect of reducing the melting point of the silicon carbide, the diamond cooling fin completely composed of the silicon carbide and the diamond can be generated by controlling the proper proportion of the diamond single crystal, the silicon powder and the silicon carbide micro-powder, and the diamond cooling fin has the excellent performance that the heat conductivity is close to that of the single crystal; the content of diamond in the diamond cooling fin can reach 75%-95%, and the heat conductivity can reach 800 w / (m.k)-1600 w / (m.k) at the normal temperature and is 2-4 times that of pure copper 386.4 w / (m.k).

Description

Technical Field

[0001] The invention relates to the technical field of diamond heat dissipation materials, in particular to a bonding diamond heat dissipation sheet and a preparation method thereof. Background Art

[0002] Diamond has the best thermal conductivity of all known materials. Its thermal conductivity is five times that of copper at room temperature and twenty-five times that of copper at liquid nitrogen temperature. Therefore, it is an excellent material for chip heat dissipation. Currently, large-scale industrial production of artificial diamond single crystals is mainly in granular form, with sizes ranging from 0.02 to 2 mm, and cannot be directly used for chip heat dissipation. With the continuous advancement of the large-scale development of China's hinged six-sided top press, the manufacturing cost of artificial diamond single crystals continues to decline. Using existing cheap artificial diamond single crystals, diamond heat sinks with excellent performance and low cost can be manufactured, which has an important role in improving the storage and conversion of high-performance chips in the microelectronics industry, new energy vehicles, photovoltaics, wind energy and other new energy sources. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a bonded diamond heat sink and a preparation method thereof.

[0004] To achieve the above object, the present invention is implemented according to the following technical solutions: One of the purposes of the present invention is to provide a method for preparing a bonded diamond heat sink, comprising the following steps: S1. Assembled bonded diamond heat sink synthetic block: The synthetic block includes a pyrophyllite square tube with a cylindrical cavity inside, a composite pyrophyllite tube is embedded in the inner wall of the cylindrical cavity of the pyrophyllite square tube, and the inner diameter of the composite pyrophyllite tube is the same as the inner diameter of the pyrophyllite square tube; a heating tube is sleeved in the composite pyrophyllite tube, heating plates are arranged at both ends of the heating tube, an insulating cup is sleeved in the heating tube, and sealing insulating plates are arranged at both ends of the insulating cup; composite pyrophyllite sealing blocks and pyrophyllite sealing blocks are arranged at the two ends of the composite pyrophyllite tube from the inside to the outside, and a conductive steel ring is arranged through the center of the composite pyrophyllite sealing block and the pyrophyllite sealing block, and the conductive steel ring The inner end surface is in contact with the outer end surface of the heating plate; a bonded diamond heat sink synthetic block is sleeved in the insulating cup, and the bonded diamond heat sink synthetic block includes a carbon tube sleeved on the inner wall of the insulating cup, and a plugging carbon sheet is respectively provided in the top and the end of the carbon tube, and a plurality of mixed powder layers composed of single crystal diamond, silicon powder and silicon carbide micropowder are laid in the carbon tube, and a graphite sheet is provided on the upper end surface and the lower end surface of each mixed powder layer; the lower end surface of the graphite sheet located in the bottom layer of the carbon tube contacts the upper end surface of the plugging carbon sheet at the lower end of the carbon tube, and the upper end surface of the graphite sheet located in the top layer of the carbon tube contacts the lower end surface of the plugging carbon sheet at the upper end of the carbon tube; S2. Preparation of bonded diamond heat sink: The above-mentioned synthesis block is loaded into the synthesis chamber of a six-sided top press, and the pressure in the synthesis chamber is increased to 3~6GPa by a staged pressure-increasing process, and the temperature reaches 1200~1700 degrees. The silicon powder and silicon carbide powder inside each layer are melted, and the single crystal diamond in the layer is bonded together. The carbon atoms on the surface of the silicon powder and the diamond single crystal react to form silicon carbide. After the single crystal diamond in the layer grows, they form connected crystals with each other, and finally a diamond heat sink composed of silicon carbide and diamond is generated. The diamond heat sink is taken out of the carbon tube and cooled to room temperature.

[0005] Furthermore, in each mixed powder layer, the mass percentage of single crystal diamond is 80%-95%, the mass percentage of silicon powder is 4.5%-25%, and the mass percentage of silicon carbide micropowder is 0.5%-5%.

[0006] Furthermore, the wall thickness of the carbon tube is 2-5 mm.

[0007] Furthermore, the thickness of the mixed powder layer formed by mixing single crystal diamond, silicon powder and silicon carbide powder is 0.5-3 mm.

[0008] Furthermore, the single crystal diamond includes 0.02-2 mm original granular single crystal diamond, 0.02-2 mm original single crystal continuous crystal, and 0.02-0.3 mm single crystal diamond crushed material.

[0009] Furthermore, the particle size of the silicon powder is 0.1-20 microns, and the particle size of the silicon carbide powder is 0.1-20 microns.

[0010] A second object of the present invention is to provide a bonded diamond heat sink prepared by the method.

[0011] Compared with the prior art, the present invention loads the synthetic block into a six-sided top press and adopts a segmented boosting process for processing. The silicon powder and silicon carbide micropowder inside each layer are melted, the single crystal diamond in the layer is bonded together, the silicon powder reacts with the carbon atoms on the surface of the diamond single crystal to generate silicon carbide, and the silicon micropowder has the effect of lowering the melting point of silicon carbide. By controlling the appropriate ratio of diamond single crystal, silicon powder and silicon carbide micropowder, a diamond heat sink completely composed of silicon carbide and diamond can be generated, which has excellent performance of thermal conductivity close to that of single crystal; the diamond content in the diamond heat sink can reach 75% to 95%, and the thermal conductivity at room temperature can reach 800w / (mk) to 1600w / (mk), which is 2 to 4 times that of pure copper 386.4w / (mk). BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The schematic diagram of the structure of the bonded diamond heat sink composite block assembled by the present invention. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the invention.

[0014] A method for preparing a bonded diamond heat sink comprises the following steps: S1. Assemble the bonded diamond heat sink block: Figure 1 As shown, the synthetic block includes a pyrophyllite square tube 1 with a cylindrical cavity inside, a composite pyrophyllite tube 2 is embedded in the inner wall of the cylindrical cavity of the pyrophyllite square tube 1, and the inner diameter of the composite pyrophyllite tube 2 is the same as the inner diameter of the pyrophyllite square tube; a heating tube 3 is sleeved in the composite pyrophyllite tube 2, heating plates 4 are provided at both ends of the heating tube 3, an insulating cup 5 (dolomite cup) is sleeved in the heating tube 3, and blocking insulating plates 6 are provided at both ends of the insulating cup 5; composite pyrophyllite blocking blocks and pyrophyllite blocking blocks 11 are provided at the two ends of the composite pyrophyllite tube 2 from the inside to the outside, a conductive steel ring 12 is provided through the center of the composite pyrophyllite blocking blocks and the pyrophyllite blocking blocks 11, and the inner end surface of the conductive steel ring 12 is in contact with the outer end surface of the heating plates 4; a bonded diamond heat sink synthetic block is sleeved in the insulating cup 5, The bonded diamond heat sink synthetic block comprises a carbon tube 7 sleeved on the inner wall of an insulating cup 5, a plugging carbon sheet 8 is respectively arranged at the top and the end of the carbon tube 7, and a plurality of mixed powder layers 10 composed of single crystal diamond, silicon powder and silicon carbide powder are laid in the carbon tube 7, wherein the mass percentage of single crystal diamond, silicon powder and silicon carbide powder in each mixed powder layer 10 is 80%-95%, the mass percentage of silicon powder is 4.5%-25%, and the mass percentage of silicon carbide powder is 0.5%-5%; a graphite sheet 9 is arranged on the upper and lower end faces of each mixed powder layer 10; the lower end face of the graphite sheet 9 of the lowest layer in the carbon tube 7 contacts the upper end face of the plugging carbon sheet 8 at the lower end of the carbon tube 7, and the upper end face of the graphite sheet 9 of the highest layer in the carbon tube 7 contacts the lower end face of the plugging carbon sheet 8 at the upper end of the carbon tube 7; S2. Preparation of bonded diamond heat sink: The above-mentioned synthetic block is loaded into the synthesis chamber of a six-sided top press, and the pressure in the synthesis chamber is increased to 3~6GPa by a staged pressure-increasing process, and the temperature reaches 1200~1700 degrees. The silicon powder and silicon carbide powder inside each layer are melted, and the single crystal diamond in the layer is bonded together. The carbon atoms on the surface of the silicon powder and the diamond single crystal react to form silicon carbide. After the single crystal diamond in the layer grows, they form connected crystals with each other, and finally a diamond heat sink composed of silicon carbide and diamond is generated. The diamond heat sink is taken out of the carbon tube and cooled to room temperature. According to actual testing, the diamond content in the diamond heat sink can reach 75%~95%.

[0015] In this embodiment, the wall thickness of the carbon tube is 2-5 mm; the thickness of the mixed powder layer formed by mixing single crystal diamond, silicon powder and silicon carbide powder is 0.5-3 mm; the single crystal diamond includes 0.02-2 mm original granular single crystal diamond, 0.02-2 mm original single crystal continuous crystal, and 0.02-0.3 mm single crystal diamond crushed material.

[0016] The prepared diamond heat sink was tested with a laser thermal conductivity meter (Germany NETZSCH laser thermal conductivity meter LFA427), and the thermal conductivity was measured at room temperature to be 800w / (mk)~1600w / (mk), which is 2~4 times that of pure copper 386.4w / (mk).

[0017] The technical solution of the present invention is not limited to the above-mentioned specific embodiments. All technical variations made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a bonded diamond heat sink, characterized in that: The following steps are involved: S1. Assembled bonded diamond heat sink synthetic block: The synthetic block includes a pyrophyllite square tube with a cylindrical cavity inside, a composite pyrophyllite tube is embedded in the inner wall of the cylindrical cavity of the pyrophyllite square tube, and the inner diameter of the composite pyrophyllite tube is the same as the inner diameter of the pyrophyllite square tube; a heating tube is sleeved in the composite pyrophyllite tube, heating plates are arranged at both ends of the heating tube, an insulating cup is sleeved in the heating tube, and sealing insulating plates are arranged at both ends of the insulating cup; composite pyrophyllite sealing blocks and pyrophyllite sealing blocks are arranged at the two ends of the composite pyrophyllite tube from the inside to the outside, and a conductive steel ring is arranged through the center of the composite pyrophyllite sealing block and the pyrophyllite sealing block, and the conductive steel ring The inner end surface is in contact with the outer end surface of the heating plate; a bonded diamond heat sink synthetic block is sleeved in the insulating cup, and the bonded diamond heat sink synthetic block includes a carbon tube sleeved on the inner wall of the insulating cup, and a plugging carbon sheet is respectively provided in the top and the end of the carbon tube, and a plurality of mixed powder layers composed of single crystal diamond, silicon powder and silicon carbide micropowder are laid in the carbon tube, and a graphite sheet is provided on the upper end surface and the lower end surface of each mixed powder layer; the lower end surface of the graphite sheet located in the bottom layer of the carbon tube contacts the upper end surface of the plugging carbon sheet at the lower end of the carbon tube, and the upper end surface of the graphite sheet located in the top layer of the carbon tube contacts the lower end surface of the plugging carbon sheet at the upper end of the carbon tube; S2. Preparation of bonded diamond heat sink: The above-mentioned synthesis block is loaded into the synthesis chamber of a six-sided top press, and the pressure in the synthesis chamber is increased to 3~6GPa by a staged pressure-increasing process, and the temperature reaches 1200~1700 degrees. The silicon powder and silicon carbide powder inside each layer are melted, and the single crystal diamond in the layer is bonded together. The carbon atoms on the surface of the silicon powder and the diamond single crystal react to form silicon carbide. After the single crystal diamond in the layer grows, they form connected crystals with each other, and finally a diamond heat sink composed of silicon carbide and diamond is generated. The diamond heat sink is taken out of the carbon tube and cooled to room temperature.

2. The method for preparing a bonded diamond heat sink according to claim 1, characterized in that: In each mixed powder layer, the mass percentage of single crystal diamond is 70%-95%, the mass percentage of silicon powder is 4.5%-25%, and the mass percentage of silicon carbide micropowder is 0.5%-5%.

3. The method for preparing a bonded diamond heat sink according to claim 1, characterized in that: The wall thickness of the carbon tube is 2-5 mm.

4. The method for preparing a bonded diamond heat sink according to claim 1, characterized in that: The thickness of the mixed powder layer formed by mixing single crystal diamond, silicon powder and silicon carbide micropowder is 0.5-3 mm.

5. The method for preparing a bonded diamond heat sink according to claim 1, characterized in that: The single crystal diamond includes 0.02-2 mm original granular single crystal diamond, 0.02-2 mm original single crystal continuous crystal, and 0.02-0.3 mm single crystal diamond crushed material.

6. The method for preparing a bonded diamond heat sink according to claim 1, characterized in that: The particle size of the silicon powder is 0.1-20 microns, and the particle size of the silicon carbide powder is 0.1-20 microns.

7. A bonded diamond heat sink prepared by the method according to any one of claims 1 to 6.

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