MIM process preparation method for ultrahigh heat-conducting composite material based on diamonds and red copper, and cold plate type liquid-cooling heat-dissipation system part made of composite material

Abstract

An MIM preparation method for an ultrahigh heat-conducting composite material based on diamonds and red copper. The method comprises the preparation of a mixture, internal mixing granulation, injection molding, and degreasing sintering. By means of the MIM process, not only can uniform mixing and high-density molding of diamonds and a red copper powder be achieved, thereby effectively overcoming the technical problems of non-uniform dispersity, low density, etc. during the preparation of a high-heat-conductivity composite material by means of a traditional process, but the shape and size of a product can also be accurately controlled, particularly during the production of a sheet material having a thickness of less than 1 mm; moreover, the heat conductivity (the heat conductivity thereof being up to 500-800 W / (m·K)) thereof is significantly improved and is significantly higher than that of a traditional metal material. In addition, by optimizing MIM process parameters and selecting raw materials having higher cost effectiveness, the present invention effectively reduces the production cost, such that large-scale use of the high heat-conducting composite material based on diamonds and red copper becomes possible, thereby satisfying the high-standard requirements of high-performance electronic equipment for heat dissipation materials.

Description

MIM process preparation method of diamond and copper-based ultra-high thermal conductivity composite material and cold plate liquid cooling system parts made of the composite material Technical Field

[0001] The present invention relates to the field of cold plate liquid cooling heat dissipation materials, and in particular to a diamond and copper-based ultra-high thermal conductivity composite material for heat dissipation of GPUs, CPUs and memories, and a metal injection molding (MIM) process preparation method thereof. Background Art

[0002] With the continued growth of high-performance computing technology and the demand for big data processing, the power density and thermal load of key computing components such as GPUs, CPUs, and memory are constantly increasing. Traditional cooling technologies are no longer able to meet the demand for efficient heat dissipation. Therefore, the development of a new heat dissipation material and its preparation method that can effectively improve heat dissipation efficiency and is suitable for high-performance electronic devices is of great significance for improving the performance of the entire cold plate liquid cooling system.

[0003] With the advancement of electronic technology, especially in data centers and high-performance computing, the computing power of server chips continues to increase, and correspondingly, the demand for heat dissipation is also increasing. To meet this challenge, liquid cooling technology has gradually become a focus of research and application. Among them, cold plate liquid cooling systems have attracted attention due to their maturity and widespread application. In this type of system, the heat dissipation device (such as the server chip) does not directly contact the coolant. Instead, the heat is dissipated through a cold plate mounted on the electronic components to be cooled. This design aims to minimize modifications to the server chip and its components while improving the operability of the entire liquid cooling system.

[0004] The cold plate has various designs, and its structure can be optimized according to the needs. For example, the internal flow channel may adopt various forms such as grooves and snap-fit ​​fins. For components with high power consumption or high heat density, the cold plate microchannel structure will become more complicated to increase the contact area and improve the heat dissipation performance. However, although optimizing the internal structure of the cold plate can improve the heat dissipation performance, improving the thermal conductivity of the material itself is crucial to enhancing the overall performance of the cold plate. Although traditional metal materials such as copper have good thermal conductivity, their performance is still difficult to meet the cooling needs of modern high-performance server chips. Therefore, the development of ultra-high thermal conductivity composite materials based on copper and high thermal conductivity materials such as diamond is aimed at providing better thermal conductivity for the cold plate, improving heat dissipation efficiency and system stability. This is exactly the purpose of the applicant. The present invention aims to prepare a diamond and copper-based composite material with high thermal conductivity through the MIM process, providing a more efficient and reliable heat dissipation solution for key computing components such as GPUs, CPUs and memories, so as to meet the heat dissipation challenges of modern high-performance computing equipment. Summary of the Invention

[0005] The present invention aims to provide a method for preparing a diamond-copper-based ultra-high thermal conductivity composite material using a metal injection molding (MIM) process. This method addresses the challenges of direct production, difficulty improving thermal conductivity, and high costs encountered by existing casting processes when producing thin sheets less than 1 mm thick. Through the MIM process, the present invention not only achieves uniform mixing of diamond and copper powders and high-density molding, effectively overcoming the technical challenges of uneven dispersion and low density associated with traditional processes for producing high-thermal conductivity composite materials, but also enables precise control of product shape and size, particularly for producing thin sheets less than 1 mm thick, while significantly improving thermal conductivity. Furthermore, by optimizing MIM process parameters and selecting more cost-effective raw materials, the present invention effectively reduces production costs, enabling the large-scale application of high-thermal conductivity diamond-copper-based composite materials, thereby meeting the high standards required for heat dissipation materials in high-performance electronic devices.

[0006] Another object of the present invention is to provide a cold plate type liquid cooling and heat dissipation system and parts made using the above composite material.

[0007] In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

[0008] A MIM preparation method for a diamond and copper-based ultra-high thermal conductivity composite material comprises the following steps:

[0009] a) using copper powder with an average particle size of 10 μm to 80 μm and diamond powder with an average particle size of 70 μm to 350 μm as raw materials;

[0010] b) mixing copper powder and diamond powder, wherein the volume fraction of the diamond powder in the composite material is 10% to 70%;

[0011] c) adding a binder and mixing uniformly, wherein the weight of the binder accounts for 5-15% of the total weight; the binder comprises polyoxymethylene, polypropylene, a compatibilizer, a plasticizer and a surfactant, and the weight ratio thereof is 80-95%: 5-15%: 0.5-5%: 0.5-5%: 0.5-5%;

[0012] d) The mixed powder material is kneaded and granulated, and then injection molded in a preheated mold through a metal injection molding process;

[0013] e) The formed product is subjected to degreasing and sintering treatment, the degreasing temperature is 130-150°C, the sintering temperature is set at 900-1080°C, and sintering is carried out in a protective atmosphere.

[0014] In an improved solution to the MIM preparation method of the above-mentioned diamond and copper-based ultra-high thermal conductive composite material, during the banburying granulation, the granulation temperature is 150-200° C., forming round or elliptical particles with a diameter of 7-14 mm.

[0015] In the improved scheme for the MIM preparation method of the above-mentioned diamond and copper-based ultra-high thermal conductivity composite material, the metal injection molding process specifically includes using a high-efficiency mixer to uniformly mix the copper powder and the diamond powder, using high-shear mixing technology to ensure the uniform dispersion of the diamond in the copper, and forming particles suitable for injection molding through a high-temperature internal mixing granulator.

[0016] In an improved solution to the MIM preparation method of the above-mentioned diamond and copper-based ultra-high thermal conductive composite material, during metal injection molding, the mold is preheated to a temperature of 90-100°C.

[0017] In an improved solution to the MIM preparation method of the above-mentioned diamond and copper-based ultra-high thermal conductivity composite material, during the degreasing and sintering process, 10-100% hydrogen and 0-90% nitrogen are injected into the furnace as protective gases.

[0018] In an improved solution to the MIM preparation method of the above-mentioned diamond and copper-based ultra-high thermal conductivity composite material, the cold plate in the system is prepared by the metal injection molding process described in claim 1. The cold plate is used for heat dissipation of GPUs, CPUs and memory, wherein the thermal conductivity of the composite material is as high as 400 to 800 W / (m·K).

[0019] A cold plate type liquid cooling system component made of diamond and copper-based ultra-high thermal conductivity composite material is a thin sheet with a thickness of less than 1 mm.

[0020] Compared with the existing technology, the beneficial effects of the present invention are as follows: due to the MIM process, not only can the uniform mixing and high-density molding of diamond and copper powders be achieved, effectively overcoming the technical difficulties of uneven dispersion and low density in the preparation of high thermal conductivity composite materials by traditional processes, but also the shape and size of the product can be precisely controlled, especially the production of thin sheet materials with a thickness of less than 1 mm while significantly improving their thermal conductivity. The thermal conductivity is as high as 500 to 800 W / (m·K), which is significantly higher than that of traditional metal materials. When applied to a cold plate liquid cooling system, it can provide an efficient heat dissipation solution and system stability for heat-generating devices such as server GPUs and CPU chips; in addition, the present invention effectively reduces production costs by optimizing MIM process parameters and selecting more cost-effective raw materials, making large-scale application of high-thermal conductivity diamond and copper-based composite materials possible, thereby meeting the high standards required for heat dissipation materials by high-performance electronic equipment.

[0021] The present invention is further described in detail below in conjunction with specific embodiments: Modes for Carrying Out the Invention

[0022] In a specific embodiment of the present invention, a diamond and copper-based ultrahigh thermal conductive composite material is prepared by a metal injection molding (MIM) process, and the detailed steps are as follows:

[0023] Materials preparation:

[0024] Copper powder: Select copper powder with an average particle size of 10 microns to 80 microns to ensure its good fluidity and formability.

[0025] Diamond powder: Diamond powder with an average particle size of 70 microns to 350 microns is used to achieve high dispersion of diamond in the composite material and excellent thermal conductivity.

[0026] The volume fraction of diamond powder in the composite material is adjusted to 10% to 70% to meet the balance between different heat dissipation requirements and cost-effectiveness.

[0027] Typically, the copper powder and diamond powder are granulated with a binder by internal kneading. The binder comprises polyoxymethylene, polypropylene, a compatibilizer, a plasticizer, and a surfactant in a weight ratio of 80-95%: 5-15%: 0.5-5%: 0.5-5%: 0.5-5%. The weight of the binder accounts for 5-15% of the total weight.

[0028] Example:

[0029] (1) Material preparation:

[0030] Copper powder: Select copper powder with an average particle size of 15 microns and good thermal conductivity, weighing 4000g, and ensure that its purity reaches more than 99.9%.

[0031] Diamond powder: Diamond powder with a particle size of 80 microns and a weight of 1050 g was selected. According to calculation, the volume fraction of the diamond powder in the composite material is approximately 40.1%.

[0032] Binder: Prepare the binder using a weight ratio of 86% polyoxymethylene, 5% polypropylene, compatibilizer, plasticizer, and surfactant: 350g (approximately 6.5% of the total weight) of the binder. The binder enhances the fluidity and injectability of the mixture while also promoting uniform mixing between the diamond powder and copper.

[0033] (2) Mixture preparation:

[0034] First, add copper powder into a high-efficiency mixer; then, slowly add diamond powder to mix. During the mixing process, to ensure that the diamond powder is evenly dispersed in the copper powder, high shear mixing technology can be used and mixing is continued for 45 minutes until the mixture is completely uniform.

[0035] (3) Internal mixing and granulation:

[0036] The mixture is transferred to a high-temperature internal mixer and granulator, where a specially formulated binder is gradually added. The temperature is set at 190°C, gradually forming round or oval particles with a diameter of 4 to 9 mm. After granulation, the feed particles are rapidly cooled to prevent structural changes and stored in a dry, cool environment to ensure stable performance.

[0037] (4) Injection molding:

[0038] First, the micro mold is preheated to 90°C in the oil channel, ensuring that no residue remains inside the mold. The prepared feedstock is then gradually added to the injection molding machine and injection molding is performed according to preset parameters to form a cold plate.

[0039] (5) Degreasing and sintering:

[0040] The molded parts are first degreased with oxalic acid at 135°C for 20 hours to completely remove the binder. The degreased parts are then transferred to a specialized sintering furnace set to 1000°C and held at that temperature for one hour. During sintering, a protective atmosphere of 85% hydrogen and 15% nitrogen is injected into the furnace to prevent oxidation or diamond carbonization of the composite material during sintering.

[0041] The above-mentioned preparation process resulted in a cold-plate, diamond-reinforced copper matrix composite material with a stable thermal conductivity of 500-550 W / (m·K), demonstrating excellent thermal conductivity. Furthermore, electron microscopic observation of its microstructure revealed that the diamonds were evenly distributed within the copper matrix, forming a strong physical bond with the copper, which provides the basis for the significant improvement in thermal conductivity.

[0042] Example:

[0043] (1) Material preparation:

[0044] Copper powder: Select copper powder with an average particle size of 80 microns and good thermal conductivity, weighing 3000g, and ensure that its purity reaches more than 97%.

[0045] Diamond powder: Diamond powder with a particle size of 100 microns and a weight of 140 g was selected. According to calculation, the volume fraction of the diamond powder in the composite material is approximately 10.63%.

[0046] Binder: Prepare the binder using a weight ratio of 80% polyoxymethylene, 15% polypropylene, 0.6% compatibilizer, 0.5% plasticizer, and 3.9% surfactant. After preparation, weigh 550g (approximately 15% of the total weight). The binder enhances the fluidity and injectability of the mixture while promoting uniform mixing between the diamond powder and copper.

[0047] (2) Mixture preparation:

[0048] First, add copper powder into a high-efficiency mixer; then, slowly add diamond powder to mix. During the mixing process, to ensure that the diamond powder is evenly dispersed in the copper powder, high shear mixing technology can be used and mixing is continued for 35 minutes until the mixture is completely uniform.

[0049] (3) Internal mixing and granulation:

[0050] The mixture is transferred to a high-temperature internal mixer and granulator, where a specially formulated binder is gradually added. The temperature is set at 170°C, gradually forming round or oval particles with a diameter of 2 to 10 mm. After granulation, the feed particles are rapidly cooled to prevent structural changes and stored in a dry, cool environment to ensure stable performance.

[0051] (4) Injection molding:

[0052] First, the micro mold is preheated to 95°C in the oil channel, ensuring that no residue remains inside the mold. The prepared feedstock is then gradually added to the injection molding machine and injection molding is performed according to preset parameters to form a cold plate.

[0053] (5) Degreasing and sintering:

[0054] The molded parts are first degreased with oxalic acid at 125°C for 15 hours to completely remove the binder. The degreased parts are then transferred to a specialized sintering furnace set to 900°C and held there for two hours. During sintering, a protective atmosphere of 50% hydrogen and 50% nitrogen is injected into the furnace to prevent oxidation or diamond carburization of the composite material during sintering.

[0055] The above-described preparation process yields a cold-plate, diamond-reinforced copper matrix composite material with a stable thermal conductivity range of 680 to 760 W / (m·K), demonstrating excellent thermal conductivity. Furthermore, electron microscopic observation of its microstructure reveals that the diamonds are uniformly distributed within the copper matrix, forming a strong physical bond with the copper, which provides the foundation for significantly improved thermal conductivity.

[0056] Example:

[0057] (1) Material preparation:

[0058] Copper powder: Select copper powder with an average particle size of 45 microns and good thermal conductivity, weighing 2500g, and ensure that its purity reaches more than 97%.

[0059] Diamond powder: Diamond powder with a particle size of 150 microns and a weight of 2200 g was selected. According to calculation, the volume fraction of the diamond powder in the composite material is approximately 69.17%.

[0060] Binder: Prepare the binder using a weight ratio of 90% polyoxymethylene, 5% polypropylene, 2% compatibilizer, 2% plasticizer, and 1% surfactant. Weigh 300g (approximately 6% of the total weight) of the binder. The binder enhances the fluidity and injectability of the mixture while also promoting uniform mixing between the diamond powder and copper.

[0061] (2) Mixture preparation:

[0062] First, add copper powder into a high-efficiency mixer; then, slowly add diamond powder to mix. During the mixing process, to ensure that the diamond powder is evenly dispersed in the copper powder, high shear mixing technology can be used and mixing is continued for 50 minutes until the mixture is completely uniform.

[0063] (3) Internal mixing and granulation:

[0064] The mixture is transferred to a high-temperature internal mixer and granulator, where a specially formulated binder is gradually added. The temperature is set at 200°C, gradually forming round or oval particles with a diameter of 7 to 14 mm. After granulation, the feed particles are rapidly cooled to prevent structural changes and stored in a dry, cool environment to ensure stable performance.

[0065] (4) Injection molding:

[0066] First, the micro mold is preheated to 98°C in the oil channel, ensuring that no residue remains inside the mold. The prepared feedstock is then gradually added to the injection molding machine and injection molding is performed according to preset parameters to form a cold plate.

[0067] (5) Degreasing and sintering:

[0068] The molded parts are first degreased with oxalic acid at 140°C for 12 hours to completely remove the binder. The degreased parts are then transferred to a specialized sintering furnace set to 1070°C and held at this temperature for three hours. During sintering, a protective atmosphere of 25% hydrogen and 75% nitrogen is injected into the furnace to prevent oxidation or diamond carbonization of the composite material during sintering.

[0069] The above-described preparation process yields a cold-plate, diamond-reinforced copper-matrix composite material with a stable thermal conductivity range of 700 to 790 W / (m·K), demonstrating excellent thermal conductivity. Furthermore, electron microscopic observation of its microstructure reveals that the diamonds are uniformly distributed within the copper matrix, forming a strong physical bond with the copper, which provides the foundation for significantly improved thermal conductivity.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. That is, any equivalent changes and modifications made according to the content of the patent application of the present invention should fall within the technical scope of the present invention.

Claims

1. A MIM preparation method for a diamond and copper-based ultra-high thermal conductive composite material, characterized in that: The following steps are involved: a) using copper powder with an average particle size of 10 μm to 80 μm and diamond powder with an average particle size of 70 μm to 350 μm as raw materials; b) mixing copper powder and diamond powder, wherein the volume fraction of the diamond powder in the composite material is 10% to 70%; c) adding a binder and mixing uniformly, wherein the weight of the binder accounts for 5-15% of the total weight; the binder comprises polyoxymethylene, polypropylene, a compatibilizer, a plasticizer and a surfactant, and the weight ratio thereof is 80-95%: 5-15%: 0.5-5%: 0.5-5%: 0.5-5%; d) The mixed powder material is kneaded and granulated, and then injection molded in a preheated mold through a metal injection molding process; e) The formed product is subjected to degreasing and sintering treatment, the degreasing temperature is 130-150°C, the sintering temperature is set at 900-1080°C, and sintering is carried out in a protective atmosphere.

2. The MIM preparation method of the diamond and copper-based ultra-high thermal conductive composite material according to claim 1, characterized in that: During the internal mixing granulation, the granulation temperature is 150-200°C, and round or oval particles with a diameter of 7-14 mm are formed.

3. The MIM preparation method of the diamond and copper-based ultra-high thermal conductive composite material according to claim 1, characterized in that: The metal injection molding process specifically includes using a high-efficiency mixer to uniformly mix copper powder and diamond powder, using high-shear mixing technology to ensure uniform dispersion of diamond in copper, and forming particles suitable for injection molding through a high-temperature internal mixing granulator.

4. The MIM preparation method of the diamond and copper-based ultra-high thermal conductive composite material according to claim 1, characterized in that: During metal injection molding, the mold is preheated to a temperature of 90-100°C.

5. The MIM preparation method of the diamond and copper-based ultra-high thermal conductive composite material according to claim 1, characterized in that: During the debinding and sintering process, 10-100% hydrogen and 0-90% nitrogen are injected into the furnace as protective gases.

6. A cold plate liquid cooling system using diamond and copper-based ultra-high thermal conductivity composite material, characterized in that: The cold plate in the system is prepared by the metal injection molding process according to claim 1. The cold plate is used for heat dissipation of GPU, CPU and memory, wherein the thermal conductivity of the composite material is as high as 400-800W / (m·K).

7. The cold plate type liquid cooling and heat dissipation system component made of diamond and copper-based ultra-high thermal conductivity composite material according to claim 6, characterized in that: The cold plate type liquid cooling and heat dissipation system component is a thin sheet with a thickness of less than 1 mm.