Method for manufacturing diamond heat spreader and diamond heat spreader

Abstract

The application discloses a preparation method of a diamond heat sink and the diamond heat sink. The preparation method comprises the following steps: providing a substrate comprising opposite first and second sides; forming a solder layer on the first side of the substrate; laying a diamond layer on the side of the solder layer away from the substrate, the diamond layer comprising a plurality of diamonds; sintering the substrate, the solder layer and the diamond layer; and arranging an electrically conductive circuit layer on the side surface of the diamond layer away from the solder layer to form the diamond heat sink. According to the embodiment of the application, the solder layer and the diamond layer are sequentially arranged on the substrate, and the substrate, the solder layer and the diamond layer are sintered, so that the diamonds are bonded to the substrate by the solder layer. Then, the electrically conductive circuit layer is arranged on the side surface of the diamond away from the solder layer to form the diamond heat sink, so that the small-size diamonds can be made by splicing, material loss is reduced, the preparation efficiency of the diamond heat sink is improved, and the preparation cost of the diamond heat sink is reduced.

Description

Technical Field

[0001] This application relates to the field of laser technology, and in particular to a method for preparing a diamond heat sink and the diamond heat sink itself. Background Technology

[0002] With the continuous increase in the output power of high-power devices such as microwave devices, power electronics, and lasers, the heat dissipation requirements for high-power devices are also increasing. Traditional packaging materials are limited by their own thermal conductivity and cannot achieve efficient heat dissipation, resulting in high junction temperatures for high-power devices and affecting their performance.

[0003] Diamond is the material with the highest known thermal conductivity, making it the best material for heat dissipation in high-power devices. However, due to limitations in diamond growth technology, diamonds are small in size, making them difficult to use as heat sinks for high-power devices. Summary of the Invention

[0004] This application provides a method for preparing a diamond heat sink and a diamond heat sink, aiming to solve the problem in the prior art that the size of diamond is small due to the limitation of diamond growth process, making it difficult to use as a heat sink to dissipate heat from high-power devices.

[0005] This application provides a method for preparing a diamond heat sink, the method comprising:

[0006] A substrate is provided, the substrate including opposing first and second sides;

[0007] A solder layer is formed on the first side of the substrate;

[0008] A diamond layer is deposited on the side of the solder layer away from the substrate, and the diamond layer includes a plurality of diamonds;

[0009] The substrate, the solder layer, and the diamond layer are sintered.

[0010] A conductive circuit layer is provided on the surface of the diamond layer opposite to the solder layer to form a diamond heat sink.

[0011] In some embodiments, sintering the substrate, the solder layer, and the diamond layer includes:

[0012] The substrate, the solder layer and the diamond layer are sintered within a first preset temperature range, where the first preset temperature range is less than or equal to 800°C.

[0013] In some embodiments, before forming a conductive circuit layer on the surface of the diamond layer opposite to the solder layer, the method further includes:

[0014] The surface of the diamond layer facing away from the solder layer is ground and polished.

[0015] In some embodiments, prior to grinding and polishing the surface of the diamond layer facing away from the solder layer, the method further includes:

[0016] Provide the first support plate;

[0017] The second side of the substrate is connected to one side of the first support plate.

[0018] In some embodiments, the provision of a conductive circuit layer on the surface of the diamond layer opposite to the solder layer includes:

[0019] A seed layer is deposited on the surface of the diamond layer opposite to the solder layer;

[0020] A conductive layer is formed on the surface of the seed layer opposite to the diamond layer;

[0021] The conductive layer and the seed layer are etched to form the conductive circuit layer.

[0022] In some embodiments, after etching the conductive layer and the seed layer to form the conductive circuit layer, the method further includes:

[0023] The surface of the conductive circuit layer facing away from the diamond layer is ground to achieve a preset thickness for the conductive circuit layer.

[0024] In some embodiments, before polishing the surface of the conductive circuit layer opposite to the diamond layer, the method further includes:

[0025] Provide a second support plate;

[0026] The second side of the substrate is connected to one side of the second support plate.

[0027] In some embodiments, the substrate is made of a metallic material; the method further includes:

[0028] Peel the substrate off one side of the second support plate;

[0029] A first metal layer is formed on the second side of the substrate.

[0030] In some embodiments, the method further includes:

[0031] A second metal layer is formed on the side of the conductive circuit layer opposite to the diamond layer.

[0032] This application embodiment also provides a diamond heat sink, the diamond heat sink comprising a diamond heat sink prepared by the diamond heat sink preparation method described above, the method comprising:

[0033] A substrate is provided, the substrate including opposing first and second sides;

[0034] A solder layer is formed on the first side of the substrate;

[0035] A diamond layer is deposited on the side of the solder layer away from the substrate, and the diamond layer includes a plurality of diamonds;

[0036] The substrate, the solder layer, and the diamond layer are sintered.

[0037] A conductive circuit layer is provided on the surface of the diamond layer opposite to the solder layer to form a diamond heat sink.

[0038] The method for fabricating a diamond heat sink provided in this application involves sequentially depositing a solder layer and a diamond layer on a substrate, and then sintering the substrate with the solder layer and the diamond layer to bond the diamond to the substrate by the solder layer. A conductive circuit layer is then deposited on the surface of the diamond layer facing away from the solder layer to form the diamond heat sink. This method enables the fabrication of small-sized diamonds in a modular fashion, reduces material waste, improves the fabrication efficiency of the diamond heat sink, and lowers the fabrication cost. Attached Figure Description

[0039] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0040] Figure 1 A flowchart illustrating one embodiment of the method for preparing a diamond heat sink provided in this application;

[0041] Figure 2 A schematic diagram of the structure after providing the substrate in the method for preparing the diamond heat sink provided in the embodiments of this application;

[0042] Figure 3 This is a schematic diagram of the structure after the solder layer is formed in the preparation method of the diamond heat sink provided in the embodiments of this application;

[0043] Figure 4 This is a schematic diagram of the structure after the diamond layer is formed in the preparation method of the diamond heat sink provided in the embodiments of this application;

[0044] Figure 5 This is a schematic diagram of the structure after the substrate and the first support plate are connected in the method for preparing the diamond heat sink provided in the embodiments of this application;

[0045] Figure 6 This is a schematic diagram of the structure after grinding the surface of the diamond layer away from the solder layer in the method for preparing the diamond heat sink provided in the embodiments of this application;

[0046] Figure 7 This is a schematic diagram of the structure after the seed layer is formed in the preparation method of the diamond heat sink provided in the embodiments of this application;

[0047] Figure 8 This is a schematic diagram of the structure after the conductive circuit layer is formed in the preparation method of the diamond heat sink provided in the embodiments of this application;

[0048] Figure 9 This is a schematic diagram of the structure after the formation of the first metal layer and the second metal layer in the method for preparing the diamond heat sink provided in the embodiments of this application;

[0049] Figure 10 This is a schematic diagram of the structure of a diamond heat sink after it has been cut into sub-heat sinks in the method for preparing a diamond heat sink according to an embodiment of this application.

[0050] Figure 11 A top view of one embodiment of the diamond heat sink provided in this application;

[0051] Figure 12 for Figure 11 Enlarged view of point A in the middle.

[0052] Diamond heat sink 200; Sub-heat sink 2000; Joint seam 2001; Substrate 210; First side surface 211; Second side surface 212; Solder layer 220; Diamond layer 230; Diamond 231; Conductive circuit layer 240; Seed layer 241; Conductive layer 242; Second metal layer 243; Positive electrode 244; Negative electrode 245; First metal layer 250; First support plate 260; Second support plate 270. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0054] The following disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0055] This application provides a method for preparing a diamond heat sink and a diamond heat sink in its embodiments. These will be described in detail below.

[0056] First, this application provides a method for preparing a diamond heat sink.

[0057] Figure 1 This is a flowchart of one embodiment of the method for preparing a diamond heat sink provided in this application. Figure 1 As shown, the method for preparing a diamond heat sink includes steps S110 to S150, which are described in detail below:

[0058] S110, a substrate 210 is provided, the substrate 210 includes a first side 211 and a second side 212 opposite to each other.

[0059] like Figure 2 As shown, the first side 211 and the second side 212 of the substrate 210 are distributed on opposite sides of the substrate 210 along the thickness direction of the substrate 210. The substrate 210 can be copper foil. The thickness of the substrate 210 can be greater than or equal to 150 μm and less than or equal to 500 μm. Of course, the substrate 210 can also be made of other metals or non-metals or other materials with high thermal conductivity.

[0060] The length and width of the substrate 210 determine the length and width of the resulting diamond heat sink 200. Therefore, the length and width of the substrate 210 can be determined according to the required size of the diamond heat sink 200. In some embodiments, the length of the substrate 210 is greater than or equal to 100 mm. Alternatively, the width of the substrate 210 is greater than or equal to 100 mm.

[0061] S120, A solder layer 220 is formed on the first side surface 211 of the substrate 210, such as Figure 3 As shown.

[0062] In some embodiments, the solder layer 220 may be made of an active solder. The solder layer 220 may be formed by printing on the first side 211 of the substrate 210. Specifically, a solder layer 220 may be formed by screen printing on the first side 211 of the substrate 210.

[0063] S130, A diamond layer 230 is deposited on the side of the solder layer 220 away from the substrate 210. The diamond layer 230 includes a plurality of diamonds 231.

[0064] like Figure 4 As shown, multiple diamonds 231 of the diamond layer 230 are laid flat on the side surface of the solder layer 220 facing away from the substrate 210. The structure of the diamonds 231 can be a sheet structure. The diamonds 231 can be single-crystal diamond sheets or polycrystalline diamond sheets. Among them, the thermal conductivity of single-crystal diamonds 231 can exceed 2000W / m*K, and the thermal conductivity of polycrystalline diamonds 231 can reach 1500W / m*K. Therefore, when the diamonds 231 are single-crystal diamond sheets, the diamond heat sink 200 prepared by the diamond heat sink preparation method provided in this application embodiment can have higher thermal conductivity.

[0065] S140, the substrate 210, solder layer 220 and diamond layer 230 are sintered.

[0066] The substrate 210, solder layer 220 and diamond layer 230 can be fixed by a fixture and then placed in a sintering furnace for sintering, so that the diamond 231 is bonded to the substrate 210 by the solder layer 220.

[0067] In some embodiments, the substrate 210, solder layer 220, and diamond layer 230 can be sintered within a first preset temperature range, where the first preset temperature range is less than or equal to 800°C. The sintering temperature of the substrate 210, solder layer 220, and diamond layer 230 can be 700°C, 750°C, etc., depending on the materials of the solder layer 220 and the substrate 210.

[0068] S150. A conductive line layer 240 is provided on the surface of the diamond layer 230 facing away from the solder layer 220 to form a diamond heat sink 200.

[0069] like Figure 8 , Figure 11 and Figure 12 As shown, by providing a conductive line layer 240 on the side of the diamond 231 facing away from the solder layer 220, the conductive line layer 240 can be electrically connected to the high-power device mounted on the diamond heat sink 200, thereby connecting the high-power device to other circuits or electronic devices and enabling the high-power device to operate normally.

[0070] The method for fabricating a diamond heat sink provided in this application involves sequentially depositing a solder layer 220 and a diamond layer 230 on a substrate 210, and then sintering the substrate 210 with the solder layer 220 and the diamond layer 230, so that the diamond 231 is bonded to the substrate 210 by the solder layer 220. Then, a conductive line layer 240 is deposited on the surface of the diamond 231 facing away from the solder layer 220 to form a diamond heat sink 200. This method enables the panelization fabrication of small-sized diamonds 231, reduces material waste, improves the fabrication efficiency of the diamond heat sink 200, and lowers the fabrication cost of the diamond heat sink 200.

[0071] In some embodiments, before the conductive line layer 240 is formed on the surface of the diamond layer 230 facing away from the solder layer 220, as described above, Figure 5 and Figure 6 As shown, the preparation method of the diamond heat sink also includes grinding and polishing the surface of the diamond layer 230 away from the solder layer 220.

[0072] Understandably, due to the differences in the thickness of the solder layer 220 and the height of the diamond layer 231, after sintering the substrate 210 with the solder layer 220 and the diamond layer 230, as... Figure 5 As shown, the diamonds 231 at different positions of the diamond layer 230 have a certain height difference. By grinding and polishing the side of the diamond layer 230 away from the solder layer 220, the surface of the diamond layer 230 away from the solder layer 220 can be made smoother, which is beneficial for setting the conductive line layer 240 on the surface of the diamond layer 230 away from the solder layer 220.

[0073] In some embodiments, before grinding and polishing the surface of the diamond layer 230 facing away from the solder layer 220, such as Figure 5 As shown, the method for preparing a diamond heat sink further includes: providing a first support plate 260; and connecting the second side surface 212 of the substrate 210 to one side surface of the first support plate 260.

[0074] By connecting the second side 212 of the substrate 210 to one side of the first support plate 260, the first support plate 260 can support the substrate 210, preventing the substrate 210 from deforming during the grinding and polishing of the diamond layer 230 away from the solder layer 220, thus affecting the grinding effect of the diamond layer 230.

[0075] The first support plate 260 can be a high-strength plate such as a sapphire plate or a glass plate. The second side 212 of the substrate 210 can be bonded to one side of the first support plate 260 with an adhesive to make the connection between the second side 212 of the substrate 210 and one side of the first support plate 260 more stable.

[0076] Of course, when the substrate 210 is thicker or has higher strength, it is not necessary to connect the substrate 210 to the first support plate 260. Instead, the diamond layer 230 can be directly ground and polished on the side away from the solder layer 220.

[0077] In some embodiments, the step of forming a conductive line layer 240 on the surface of the diamond layer 230 opposite to the solder layer 220 may include steps S151 to S153, which are described in detail below:

[0078] S151, such as Figure 7 As shown, a seed layer 241 is deposited on the surface of the diamond layer 230 on the side opposite to the solder layer 220.

[0079] A seed layer 241 can be formed by depositing a seed layer 241 on the surface of the diamond layer 230 facing away from the solder layer 220 using physical vapor deposition. The material of the seed layer 241 includes titanium / copper (Ti / Cu) and chromium / copper (Cr / Cu).

[0080] In some embodiments, before the seed layer 241 is deposited on the surface of the diamond layer 230 opposite to the solder layer 220, such as Figures 6 to 7 As shown, the method for preparing a diamond heat sink further includes: peeling the substrate 210 from one side of the first support plate 260.

[0081] Understandably, during the deposition of the seed layer 241 on the surface of the diamond layer 230 facing away from the solder layer 220, the substrate 210 is in a high-temperature environment, approximately 300°C. This can easily cause the adhesive between the second side 212 of the substrate 210 and one side of the first support plate 260 to detach, thus affecting the deposition of the seed layer 241 on the surface of the diamond layer 230 facing away from the solder layer 220. By peeling the substrate 210 from one side of the first support plate 260, the impact of the detachment of the substrate 210 from the first support plate 260 on the deposition of the seed layer 241 can be avoided.

[0082] In some embodiments, the first support plate 260 can be removed by laser stripping technology to make the separation of the first support plate 260 from the substrate 210 more convenient.

[0083] Of course, when the adhesive between the second side surface 212 of the substrate 210 and one side surface of the first support plate 260 can withstand a high temperature, or when the second side surface 212 of the substrate 210 and one side surface of the first support plate 260 are connected by other means, the first support plate 260 may not be peeled off during the deposition of the seed layer 241.

[0084] S152, such as Figure 8 As shown, a conductive layer 242 is formed on the surface of the seed layer 241 facing away from the diamond layer 230.

[0085] The conductive layer 242 can be made of copper or other metals. The conductive layer 242 can be formed on the side of the seed layer 241 opposite to the diamond layer 230 by direct copper plating (DPC).

[0086] S153. The conductive layer 242 and the seed layer 241 are etched to form the conductive circuit layer 240.

[0087] By etching the conductive layer 242 and the seed layer 241, a portion of the material in the conductive layer 242 and the seed layer 241 can be removed, and the unetched portions of the conductive layer 242 and the seed layer 241 form the conductive circuit layer 240. The conductive layer 240 can be formed by etching the conductive layer 242 and the seed layer 241 using a photolithography process.

[0088] In some embodiments, after etching the conductive layer 242 and seed layer 241 to form the conductive circuit layer 240, the method for preparing the diamond heat sink further includes: grinding the surface of the conductive circuit layer 240 facing away from the diamond layer 230 to achieve a preset thickness. By grinding the surface of the conductive circuit layer 240 facing away from the diamond layer 230 after its formation, the conductive circuit layer 240 can achieve the required thickness.

[0089] In some embodiments, before grinding the surface of the conductive line layer 240 away from the diamond layer 230, the method for preparing the diamond heat sink further includes: providing a second support plate 270; and connecting the second side surface 212 of the substrate 210 to one side surface of the second support plate 270.

[0090] By connecting the second side surface 212 of the substrate 210 to one side surface of the second support plate 270, the second support plate 270 can support the substrate 210, preventing the substrate 210 from deforming during the grinding process of the conductive circuit layer 240 on the side away from the diamond layer 230, thus affecting the grinding effect of the conductive circuit layer 240 on the side away from the diamond layer 230.

[0091] The second support plate 270 can be a high-strength plate such as a sapphire plate or a glass plate. The second side 212 of the substrate 210 can be bonded to one side of the second support plate 270 with an adhesive to make the connection between the second side 212 of the substrate 210 and one side of the second support plate 270 more stable. The second support plate 270 and the first support plate 260 can be the same support plate or two different support plates.

[0092] Of course, when the substrate 210 is thicker or has higher strength, it is not necessary to connect the substrate 210 to the second support plate 270. Instead, the surface of the conductive line layer 240 facing away from the diamond layer 230 can be ground directly.

[0093] In some embodiments, the substrate 210 is made of a metallic material. For example... Figures 8 to 9 As shown, the preparation method of the diamond heat sink also includes steps S160 and S170, which are described in detail below:

[0094] S160, peel the substrate 210 from one side of the second support plate 270.

[0095] The second support plate 270 can be removed using laser stripping technology, making it easier to separate the second support plate 270 from the substrate 210.

[0096] S170, A first metal layer 250 is formed on the second side surface 212 of the substrate 210.

[0097] A first metal layer 250 can be formed on the second side 212 of the substrate 210 by electroplating. The material of the first metal layer 250 includes nickel / gold (Ni / Au), silver (Ag), etc.

[0098] In some embodiments, the method for preparing a diamond heat sink further includes forming a second metal layer 243 on the side of the conductive circuit layer 240 opposite to the diamond layer 230.

[0099] Specifically, a second metal layer 243 can be formed on the side of the conductive circuit layer 240 opposite to the diamond layer 230 by electroplating. The material of the second metal layer 243 includes nickel / gold (Ni / Au), silver (Ag), etc. Specifically, the second side 212 of the substrate 210 and the side of the conductive circuit layer 240 opposite to the diamond layer 230 can be electroplated simultaneously to form the first metal layer 250 and the second metal layer 243.

[0100] In some embodiments, such as Figure 10 As shown, the preparation method of the diamond heat sink also includes cutting the diamond heat sink 200 to form multiple sub-heat sinks 2000.

[0101] The diamond heat sink 200 can be cut using a laser to form multiple sub-heat sinks 2000. Each sub-heat sink 2000 can be used to mount high-power devices. Of course, other methods can also be used to cut the diamond heat sink 200 to form multiple sub-heat sinks 2000.

[0102] Alternatively, each sub-heat sink 2000 can have the same structure, or some of the sub-heat sinks 2000 or each sub-heat sink 2000 can have different structures.

[0103] Specifically, such as Figure 10 , Figure 11 and Figure 12 As shown, the diamond heat sink 200 includes multiple sub-heat sinks 2000, with a splicing seam 2001 formed between adjacent sub-heat sinks 2000. The diamond heat sink 200 can be cut along the splicing seam 2001 to divide it into multiple sub-heat sinks 2000. The conductive circuit layer 240 on each sub-heat sink 2000 includes a positive electrode 244 and a negative electrode 245 that are isolated from each other. When a high-power device is mounted on the sub-heat sink 2000, the positive electrode 244 and the negative electrode 245 are electrically connected to the high-power device, respectively.

[0104] Of course, when the size of the diamond heat sink 200 is small, high-power devices can be directly mounted on the diamond heat sink 200 without cutting the diamond heat sink 200.

[0105] This application also provides a diamond heat sink, which includes a diamond heat sink prepared by the preparation method of the diamond heat sink in any of the above embodiments. The specific structure of the preparation method of the diamond heat sink is as described in the above embodiments. Since this diamond heat sink adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0106] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0107] The preparation method of a diamond heat sink and the diamond heat sink provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0108] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0109] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0110] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

Claims

1. A method for preparing a diamond heat sink, characterized in that, The method includes: A substrate is provided, the substrate including opposing first and second sides; A solder layer is formed on the first side of the substrate; A diamond layer is deposited on the side of the solder layer away from the substrate, and the diamond layer includes a plurality of diamonds; The substrate, the solder layer and the diamond layer are sintered to bond the diamond to the substrate by the solder layer. The surface of the diamond layer facing away from the solder layer is ground and polished. A conductive circuit layer is provided on the side of the diamond layer away from the solder layer to form a diamond heat sink. The diamond heat sink is cut to form a plurality of sub-heat sinks. A splicing seam is formed between two adjacent sub-heat sinks. The conductive circuit layer on each sub-heat sink includes a positive electrode and a negative electrode that are isolated from each other. The provision of a conductive circuit layer on the surface of the diamond layer opposite to the solder layer includes: A seed layer is deposited on the surface of the diamond layer opposite to the solder layer; A conductive layer is formed on the surface of the seed layer opposite to the diamond layer; The conductive layer and the seed layer are etched to form the conductive circuit layer.

2. The method for preparing a diamond heat sink as described in claim 1, characterized in that, The sintering of the substrate, the solder layer, and the diamond layer includes: The substrate, the solder layer and the diamond layer are sintered within a first preset temperature range, wherein the first preset temperature range is less than or equal to 800°C.

3. The method for preparing a diamond heat sink as described in claim 1, characterized in that, Before grinding and polishing the surface of the diamond layer facing away from the solder layer, the method further includes: Provide the first support plate; The second side of the substrate is connected to one side of the first support plate.

4. The method for preparing a diamond heat sink as described in claim 1, characterized in that, After etching the conductive layer and the seed layer to form the conductive circuit layer, the method further includes: The surface of the conductive circuit layer facing away from the diamond layer is ground to achieve a preset thickness for the conductive circuit layer.

5. The method for preparing a diamond heat sink as described in claim 4, characterized in that, Before grinding the surface of the conductive circuit layer opposite to the diamond layer, the method further includes: Provide a second support plate; The second side of the substrate is connected to one side of the second support plate.

6. The method for preparing a diamond heat sink as described in claim 5, characterized in that, The substrate is made of a metallic material; the method further includes: Peel the substrate off one side of the second support plate; A first metal layer is formed on the second side of the substrate.

7. The method for preparing a diamond heat sink as described in claim 4, characterized in that, The method further includes: A second metal layer is formed on the side of the conductive circuit layer opposite to the diamond layer.

8. A diamond heat sink, characterized in that, The diamond heat sink includes the diamond heat sink prepared by the method described in any one of claims 1 to 7.

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