Diamond copper heat dissipation structure and preparation method thereof

Abstract

The invention discloses a diamond copper heat dissipation structure and a preparation method thereof, and belongs to the technical field of semiconductor materials. The diamond copper heat dissipation structure comprises a middle high-heat-conductivity area and a peripheral low-heat-conductivity area. The high-heat-conductivity area is formed by mixing and pressing fine-particle copper powder and diamond powder; the low-heat-conductivity area is formed by pressing one or two of coarse-particle copper powder and diamond powder, and at least comprises the coarse-particle copper powder; the particle size of the fine-particle copper powder is smaller than 45 microns; the particle size of the coarse particle copper powder is larger than or equal to 45 micrometers. The low-heat-conductivity area is used for assembling a circuit area which does not produce heat or produces extremely low heat, and the high-heat-conductivity area is used for assembling an area which produces high heat, such as the position of a high-power-consumption chip. The manufacturing cost can be reduced to a certain extent in the batch application process, and the method has the advantages of high heat conductivity and low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor materials and relates to a diamond copper heat dissipation structure and a preparation method thereof. Background Art

[0002] With the widespread application of high-power lasers and highly integrated semiconductor devices in optical communications, advanced manufacturing, and new energy, the rapid increase in device power density and integration has led to a sharp increase in the heat generated during operation. Heat dissipation has become a core bottleneck restricting the performance, lifespan, and reliability of these devices. Traditional heat dissipation materials (such as copper, aluminum, and silicon carbide) have limited thermal conductivity and are unable to meet the stringent thermal management efficiency requirements of high-power density devices. This can easily lead to localized overheating, concentrated thermal stress, and thermal failure of the material, resulting in device performance degradation or even damage.

[0003] To address this challenge, existing technologies have attempted to use diamond as an alternative heat dissipation material. Diamond has high thermal conductivity (1500 W / m·K -2200 W / m·K), low thermal expansion coefficient (1.1×10 -6 / ℃) and excellent chemical stability, showing significant advantages in thermal conduction efficiency and thermal stability, which can theoretically significantly improve the heat dissipation performance of the device.

[0004] However, practical applications of diamond materials still face the following key challenges. The preparation of diamond single crystal substrates or thin films relies on complex processes such as high pressure and high temperature or chemical vapor deposition, which require high equipment investment and low production efficiency, resulting in material costs far exceeding those of traditional heat dissipation materials. Furthermore, as the hardest material in nature, diamond requires specialized equipment and processes for cutting, polishing, and fabricating micro-nanostructures, further increasing the complexity and cost of device manufacturing.

[0005] Therefore, there is an urgent need to develop a heat dissipation structure that has high thermal conductivity, low cost and is easy to process, so as to break through the performance bottleneck of existing heat dissipation solutions and promote the further development of high-power lasers and highly integrated semiconductor devices. Summary of the Invention

[0006] The object of the present invention is to provide a diamond copper heat dissipation structure and a preparation method thereof, so as to solve the technical problems of low thermal conductivity and high processing cost of the heat conduction structure in the prior art.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a diamond-copper heat dissipation structure, comprising a high thermal conductivity region in the middle and low thermal conductivity regions surrounding the region; the high thermal conductivity region is formed by pressing a mixture of fine-grained copper powder and diamond powder; the low thermal conductivity region is formed by pressing one or both of coarse-grained copper powder and diamond powder, and includes at least coarse-grained copper powder; the particle size of the fine-grained copper powder is less than 45 microns; and the particle size of the coarse-grained copper powder is greater than or equal to 45 microns.

[0008] Furthermore, the thermal conductivity of the high thermal conductivity region is 500 W / (m·K) to 750 W / (m·K); and the thermal conductivity of the low thermal conductivity region is lower than 430 W / (m·K).

[0009] Furthermore, the high thermal conductivity region is square; the low thermal conductivity region is circular, and a square hole for pressing the high thermal conductivity region is left in the middle of the low thermal conductivity region.

[0010] Furthermore, a transition layer is provided at the junction between the high thermal conductivity region and the low thermal conductivity region; the material of the transition layer is tungsten.

[0011] In a second aspect, the present invention provides a method for preparing a diamond copper heat dissipation structure, comprising the following steps: Cleaning diamond powder and copper powder; dividing the copper powder into fine-grained copper powder and coarse-grained copper powder; Mixing fine-grained copper powder and diamond powder and loading them into corresponding high thermal conductivity areas of a pressing mold; loading a mixture of coarse-grained copper powder and diamond powder or coarse-grained copper powder into corresponding low thermal conductivity areas of the pressing mold; obtaining an assembled pressing mold; The assembled pressing mold is pressed into shape using a pressing process to obtain a diamond copper heat dissipation structure.

[0012] Furthermore, the diamond powder cleaning process includes: first cleaning the diamond powder with piranha solution, then cleaning the diamond powder with acetone, alcohol and deionized water respectively by ultrasonic oscillation, and finally drying with nitrogen.

[0013] Furthermore, the copper powder cleaning process includes: using acetone, isopropyl alcohol and deionized water to clean the copper powder by ultrasonic oscillation respectively, and finally vacuum drying.

[0014] Furthermore, the mixing volume ratio of fine-grained copper powder and diamond powder in the high thermal conductivity region is (4-8): (2-6); and the mixing volume ratio of coarse-grained copper powder and diamond powder in the low thermal conductivity region is (4-9): (1-6).

[0015] Furthermore, in the steps of mixing fine-grained copper powder and diamond powder and loading the mixture into the corresponding high thermal conductivity area of ​​the pressing mold; loading the mixture of coarse-grained copper powder and diamond powder or the coarse-grained copper powder into the corresponding low thermal conductivity area of ​​the pressing mold; and obtaining the assembled pressing mold, the mixing process uses a ball mill, a V-type mixer or a stirring mixer, and the mixing time is 1 to 4 hours.

[0016] Furthermore, the pressing process adopts cold pressing, hot pressing or static pressing method.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a diamond copper heat dissipation structure and a preparation method thereof, wherein a high thermal conductivity region is formed by pressing a mixture of fine-grained copper powder and diamond powder; a mixture of coarse-grained copper powder and diamond powder or coarse-grained copper powder is formed as a low thermal conductivity region; and a diamond copper heat dissipation structure is prepared. The low thermal conductivity region is used to assemble circuit regions that do not generate heat or generate very low heat, and the high thermal conductivity region is used to assemble regions that generate higher heat, such as the location of high-power chips. Diamond has extremely high thermal conductivity, hardness, and chemical stability, while copper has good electrical conductivity and formability. The present invention combines the two, and the diamond copper heat dissipation structure can provide excellent thermal conductivity performance in harsh environments such as high temperature and high pressure, and is particularly suitable for applications such as electronic packaging, radiators, and cutting tools. The manufacturing cost can be reduced to a certain extent during mass application, and the advantages of high thermal conductivity and low cost are combined. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a flow chart of a method for preparing a diamond copper heat dissipation structure of the present invention; Figure 2 This is a structural schematic diagram of a diamond copper heat dissipation structure of the present invention.

[0020] Among them, 1-high thermal conductivity area; 2-low thermal conductivity area. DETAILED DESCRIPTION

[0021] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0022] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0023] All features, such as values, amounts, contents, and concentrations, described herein as numerical ranges or percentage ranges are provided for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0024] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0025] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0026] The present invention is described in further detail below with reference to the accompanying drawings: See also Figure 2 , an embodiment of the present invention discloses a diamond copper heat dissipation structure, including a high thermal conductivity region 1 in the middle and low thermal conductivity regions 2 on all sides; the high thermal conductivity region 1 is formed by pressing a mixture of fine-grained copper powder and diamond powder; the low thermal conductivity region 2 is pressed by pressing one or both of coarse-grained copper powder and diamond powder, and at least includes coarse-grained copper powder; the particle size of the fine-grained copper powder is less than 45 microns; the particle size of the coarse-grained copper powder is greater than or equal to 45 microns. Diamond has extremely high thermal conductivity, hardness and chemical stability, while copper has good electrical conductivity and formability. The present invention combines the two, and the prepared diamond copper heat dissipation structure can provide excellent thermal conductivity performance in harsh environments such as high temperature and high pressure, and is particularly suitable for applications such as electronic packaging, radiators, and cutting tools.

[0027] In a feasible embodiment of the present invention, the thermal conductivity of the high thermal conductivity region 1 is 500 W / (m·K)~750 W / (m·K); the thermal conductivity of the low thermal conductivity region 2 is lower than 430 W(m·K). The high thermal conductivity region 1 is square; the low thermal conductivity region 2 is circular, and a square hole is left in the middle of the low thermal conductivity region 2 for pressing the high thermal conductivity region 1. Preferably, the bonding interface between the high thermal conductivity region 1 and the low thermal conductivity region 2 is prone to form holes or debonding, and the interface bonding can be improved by including but not limited to a tungsten transition layer. In the invented diamond copper heat dissipation structure, the corresponding position of the high thermal conductivity region 2 is the area with higher heat generation in the circuit, which is 100%~300% of the actual heat generation area. The remaining positions are low thermal conductivity regions 3.

[0028] See also Figure 1 The embodiment of the present invention discloses a method for preparing a diamond copper heat dissipation structure, comprising the following steps: Step 1: Cleaning diamond powder and copper powder; In this step, the cleaning process of the diamond powder includes: first, cleaning the diamond powder with piranha solution, then cleaning the diamond powder with acetone, alcohol and deionized water by ultrasonic oscillation, and finally drying with nitrogen.

[0029] The cleaning process of the copper powder includes: using acetone, isopropyl alcohol and deionized water to clean the copper powder by ultrasonic oscillation respectively, and finally vacuum drying.

[0030] Step 2: Separate the copper powder into fine-grained copper powder and coarse-grained copper powder; In this step, the particle size of the fine copper powder is less than 45 microns; the particle size of the coarse copper powder is greater than or equal to 45 microns; Step 3: Mix fine-grained copper powder and diamond powder and load them into the corresponding high thermal conductivity area 1 of the pressing mold; load the mixture of coarse-grained copper powder and diamond powder or coarse-grained copper powder into the corresponding low thermal conductivity area 2 of the pressing mold; and obtain an assembled pressing mold; In this step, the volume ratio of fine copper powder to diamond powder in the high thermal conductivity region 1 is (4-8):(2-6); the volume ratio of coarse copper powder to diamond powder in the low thermal conductivity region 2 is (4-9):(1-6). The specific sizes of the high thermal conductivity region 1 and the low thermal conductivity region 2 are designed based on actual assembly requirements.

[0031] The mixing process uses a ball mill, a V-type mixer or a stirring mixer to mix the powders for 1 to 4 hours to prevent agglomeration caused by excessive mixing.

[0032] Step 4: Use a pressing process to press the powder inside the assembled pressing mold to obtain a diamond copper heat dissipation structure.

[0033] In this step, the pressing process is performed using methods including, but not limited to, cold pressing, hot pressing, or static pressing. Cold pressing employs a pressure of 50 MPa to 500 MPa, with the specific pressure determined based on the powder particle size and shape. Hot pressing employs a pressure of 5 MPa to 50 MPa. Static pressing employs a pressure of 100 MPa to 300 MPa. The target density of the resulting diamond copper heat dissipation structure block should be close to the theoretical density (>95%).

[0034] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0035] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0036] Example 1: 1) Clean the diamond powder with piranha solution for 5 minutes, then ultrasonically clean the diamond powder with acetone, alcohol, and deionized water for 5 minutes each, and finally blow dry with nitrogen.

[0037] 2) The copper powder was cleaned with acetone, isopropyl alcohol, and deionized water in sequence for 5 min each, and then vacuum dried.

[0038] 3) Separating the copper powder into fine copper powder (particle size less than 45 microns) and coarse copper powder (particle size greater than or equal to 45 microns); 4) Fine-grained copper powder and diamond powder are mixed in a ball mill for 2 hours and then loaded into the corresponding high thermal conductivity region 1 of the pressing mold, corresponding to the assembly location of high-power chips or other types of electronic components that generate a lot of heat. The volume ratio of fine-grained copper powder to diamond powder in high thermal conductivity region 1 is 8:2. Coarse-grained copper powder and diamond powder are mixed in a ball mill for 2 hours and then loaded into the corresponding low thermal conductivity region 2 of the pressing mold. The volume ratio of coarse-grained copper powder to diamond powder in low thermal conductivity region 2 is 8:2, and low thermal conductivity region 2 is located around high thermal conductivity region 1. In this embodiment, high thermal conductivity region 1 is designed as a square area with an area of ​​3 mm × 3 mm. Low thermal conductivity region 2 is circular with an overall scale of 2 inches. The assembled pressing mold is completed.

[0039] 5) The assembled pressing mold is cold pressed to form the powder inside, and the thickness after pressing is 0.5mm.

[0040] Test results show that the thermal conductivity of high-conductivity region 1 is 529 W / (m·K), while the thermal conductivity of low-conductivity region 2 is 361 W / (m·K). The production process of this embodiment does not require expensive and complex equipment, has low production environment requirements, and does not require the clean room environment required by processes such as semiconductor epitaxy, resulting in extremely low manufacturing costs.

[0041] Example 2: 1) Clean the diamond powder with piranha solution for 5 minutes, then ultrasonically clean the diamond powder with acetone, alcohol, and deionized water for 5 minutes each, and finally blow dry with nitrogen.

[0042] 2) The copper powder was cleaned with acetone, isopropyl alcohol, and deionized water in sequence for 5 min each, and then vacuum dried.

[0043] 3) Separating the copper powder into fine copper powder (particle size less than 45 microns) and coarse copper powder (particle size greater than or equal to 45 microns); 4) Fine-grained copper powder and diamond powder are mixed in a mixer for 1 hour and then loaded into the corresponding high thermal conductivity region 1 of the pressing mold, corresponding to the assembly location of high-power chips or other types of electronic components that generate a large amount of heat. The volume ratio of the fine-grained copper powder to the diamond powder in the high thermal conductivity region 1 is 5:5. Coarse-grained copper powder and diamond powder are mixed in a mixer for 1 hour and then loaded into the corresponding low thermal conductivity region 2 of the pressing mold. The volume ratio of the coarse-grained copper powder to the diamond powder in the low thermal conductivity region 2 is 4:6, and the low thermal conductivity region 2 is located around the high thermal conductivity region 1. In this embodiment, the high thermal conductivity region 1 is a square region with an area of ​​3 mm × 3 mm. The low thermal conductivity region 2 is a circular region with an overall size of 2 inches. The assembled pressing mold is obtained.

[0044] 5) The assembled pressing mold is statically pressed to form the powder inside, and the thickness after pressing is 1mm.

[0045] Test results show that the thermal conductivity of high-conductivity region 1 is 690 W / (m·K), while the thermal conductivity of low-conductivity region 2 is 425 W / (m·K). The production process of this embodiment does not require expensive and complex equipment, has low production environment requirements, and does not require the clean room environment required by processes such as semiconductor epitaxy, resulting in extremely low manufacturing costs.

[0046] Example 3: 1) Clean the diamond powder with piranha solution for 5 minutes, then ultrasonically clean the diamond powder with acetone, alcohol, and deionized water for 5 minutes each, and finally blow dry with nitrogen.

[0047] 2) The copper powder was cleaned with acetone, isopropyl alcohol, and deionized water in sequence for 5 min each, and then vacuum dried.

[0048] 3) Separating the copper powder into fine copper powder (particle size less than 45 microns) and coarse copper powder (particle size greater than or equal to 45 microns); 4) Fine-grained copper powder and diamond powder are mixed in a V-type mixer for 3 hours and then loaded into the corresponding high thermal conductivity region 1 of the pressing mold, corresponding to the assembly location of high-power chips or other types of electronic components that generate a lot of heat. The volume ratio of fine-grained copper powder to diamond powder in high thermal conductivity region 1 is 6:4. Coarse-grained copper powder and diamond powder are mixed in a V-type mixer for 3 hours and then loaded into the corresponding low thermal conductivity region 2 of the pressing mold. The volume ratio of coarse-grained copper powder to diamond powder in low thermal conductivity region 2 is 7:3. Low thermal conductivity region 2 is located around high thermal conductivity region 1. In this embodiment, high thermal conductivity region 1 is designed as a square area with an area of ​​3 mm × 3 mm. Low thermal conductivity region 2 is circular with an overall scale of 2 inches. The assembled pressing mold is completed.

[0049] 5) The assembled pressing mold is hot pressed to press the powder inside into a shape with a thickness of 10 mm.

[0050] Test results show that the thermal conductivity of high-conductivity region 1 is 633 W / (m·k), while the thermal conductivity of low-conductivity region 2 is 383 W / (m·k). The production process of this embodiment does not require expensive and complex equipment, has low production environment requirements, and does not require the clean room environment required by processes such as semiconductor epitaxy, resulting in extremely low manufacturing costs.

[0051] Example 4: 1) Clean the diamond powder with piranha solution for 5 minutes, then ultrasonically clean the diamond powder with acetone, alcohol, and deionized water for 5 minutes each, and finally blow dry with nitrogen.

[0052] 2) The copper powder was cleaned with acetone, isopropyl alcohol, and deionized water in sequence for 5 min each, and then vacuum dried.

[0053] 3) Separating the copper powder into fine copper powder (particle size less than 45 microns) and coarse copper powder (particle size greater than or equal to 45 microns); 4) Fine-grained copper powder and diamond powder are mixed in a mixer for 4 hours and then loaded into the corresponding high thermal conductivity region 1 of the pressing mold, corresponding to the assembly location of high-power chips or other types of electronic components that generate a lot of heat. The volume ratio of fine-grained copper powder to diamond powder in high thermal conductivity region 1 is 4:6. Coarse-grained copper powder is then loaded into the corresponding low thermal conductivity region 2 of the pressing mold, with low thermal conductivity region 2 located around high thermal conductivity region 1. In this embodiment, high thermal conductivity region 1 is designed as a square region with an area of ​​3 mm x 3 mm. Low thermal conductivity region 2 is circular with an overall scale of 2 inches. The assembled pressing mold is completed.

[0054] 5) The assembled pressing mold is cold pressed to form the powder inside, and the thickness after pressing is 3.5 mm.

[0055] Test results show that the thermal conductivity of high-conductivity region 1 is 742 W / (m·K), while the thermal conductivity of low-conductivity region 2 is 320 W / (m·K). The production process of this embodiment does not require expensive and complex equipment, has low production environment requirements, and does not require the clean room environment required by processes such as semiconductor epitaxy, resulting in extremely low manufacturing costs.

[0056] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A diamond copper heat dissipation structure, characterized in that: The invention comprises a high thermal conductivity region (1) in the middle and low thermal conductivity regions (2) around the region; the high thermal conductivity region (1) is formed by pressing a mixture of fine-grained copper powder and diamond powder; the low thermal conductivity region (2) is formed by pressing one or both of coarse-grained copper powder and diamond powder, and at least comprises coarse-grained copper powder; the particle size of the fine-grained copper powder is less than 45 microns; the particle size of the coarse-grained copper powder is greater than or equal to 45 microns.

2. The diamond copper heat dissipation structure according to claim 1, characterized in that: The thermal conductivity of the high thermal conductivity region (1) is 500 W / (m·K) to 750 W / (m·K); and the thermal conductivity of the low thermal conductivity region (2) is lower than 430 W / (m·K).

3. The diamond copper heat dissipation structure according to claim 1, characterized in that: The high thermal conductivity region (1) is square; the low thermal conductivity region (2) is circular, and a square hole for pressing the high thermal conductivity region (1) is left in the middle of the low thermal conductivity region (2).

4. The method for preparing a diamond copper heat dissipation structure according to claim 1, wherein: A transition layer is provided at the junction between the high thermal conductivity region (1) and the low thermal conductivity region (2); the material of the transition layer is tungsten.

5. The method for preparing a diamond copper heat dissipation structure according to any one of claims 1 to 4, characterized in that: The following steps are involved: Cleaning diamond powder and copper powder; dividing the copper powder into fine-grained copper powder and coarse-grained copper powder; Mixing fine-grained copper powder and diamond powder and loading them into the corresponding high thermal conductivity area (1) of the pressing mold; loading a mixture of coarse-grained copper powder and diamond powder or coarse-grained copper powder into the corresponding low thermal conductivity area (2) of the pressing mold; obtaining an assembled pressing mold; The assembled pressing mold is pressed into shape using a pressing process to obtain a diamond copper heat dissipation structure.

6. The method for preparing a diamond copper heat dissipation structure according to claim 5, characterized in that: The diamond powder cleaning process includes: firstly, cleaning the diamond powder with piranha solution, then respectively cleaning the diamond powder with acetone, alcohol and deionized water by ultrasonic oscillation, and finally drying the diamond powder with nitrogen.

7. The method for preparing a diamond copper heat dissipation structure according to claim 5, characterized in that: The copper powder cleaning process includes: using acetone, isopropyl alcohol and deionized water to clean the copper powder in sequence by ultrasonic oscillation, and finally performing vacuum drying.

8. The method for preparing a diamond copper heat dissipation structure according to claim 5, characterized in that: The mixing volume ratio of fine-grained copper powder and diamond powder in the high thermal conductivity region (1) is (4-8): (2-6); and the mixing volume ratio of coarse-grained copper powder and diamond powder in the low thermal conductivity region (2) is (4-9): (1-6).

9. The method for preparing a diamond copper heat dissipation structure according to claim 5, characterized in that: The fine-grained copper powder and diamond powder are mixed and loaded into the corresponding high thermal conductivity area (1) of the pressing mold; the mixture of coarse-grained copper powder and diamond powder or the coarse-grained copper powder is loaded into the corresponding low thermal conductivity area (2) of the pressing mold; in the step of obtaining the assembled pressing mold, the mixing process adopts a ball mill, a V-type mixer or a stirring mixer, and the mixing time is 1 to 4 hours.

10. The method for preparing a diamond copper heat dissipation structure according to claim 5, characterized in that: The pressing process adopts cold pressing, hot pressing or static pressing method.

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