Method of welding a water-cooled disk body

Abstract

This invention relates to the field of semiconductor equipment technology, and more particularly to a welding method for a water-cooled plate. The welding method includes the following steps: pre-treating the surface of the water-cooled plate to remove the oxide film on the surface of the plate and the interface to be welded. The water-cooled plate is placed into the welding chamber of a diffusion welding pressure device. A vacuum device is activated to evacuate the welding chamber. Current is applied to the water-cooled plate through electrodes to form a closed current loop; the Joule heat generated at the interface to be welded is used to raise the temperature of the interface to the diffusion welding temperature, while controlling the temperature of the non-welding area of ​​the water-cooled plate to not exceed 500°C. Once the interface to be welded reaches the diffusion welding temperature, a preset pressure is applied to the water-cooled plate and held at that temperature and pressure for a preset time. After the holding time and pressure are completed, heating is stopped and the pressure is released; after cooling, a welded water-cooled plate is obtained. This welding method for water-cooled plates can reduce the deformation of the water-cooled plate and the collapse of the cooling channels after welding.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a welding method for a water-cooled plate. Background Technology

[0002] In semiconductor manufacturing, precise temperature control of the wafer directly affects the chip processing accuracy and yield. As a core component of the wafer cooling system, the water-cooled tray has its working surface in direct contact with the wafer and is equipped with precision cooling channels. A circulating cooling medium rapidly removes processing heat, achieving stable temperature control of the wafer.

[0003] The water-cooled plate is primarily encapsulated using vacuum diffusion welding technology. However, traditional vacuum diffusion welding requires heating the entire water-cooled plate to the welding temperature, resulting in excessive overall heat input and commonly causing significant welding deformation and severe cooling channel collapse. The deformed water-cooled plate exhibits reduced flatness, which in turn affects its bonding with the wafer; the collapse of the cooling channel cross-section increases the flow resistance of the cooling medium, reduces heat exchange efficiency, and ultimately diminishes the cooling performance of the water-cooled plate.

[0004] Therefore, there is an urgent need to design a welding method for water-cooled plates to solve the above technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a welding method for water-cooled disks that can reduce deformation of the water-cooled disks and collapse of cooling channels after welding, thereby ensuring the cooling effect of the water-cooled disks on the wafers.

[0006] To achieve this objective, the present invention adopts the following technical solution: This invention provides a welding method for a water-cooled plate body, comprising: S1. Perform surface pretreatment on the water-cooled plate to remove the oxide film on the surface of the water-cooled plate and the interface to be welded. S2. The water-cooled plate body, which has been pretreated by S1, is installed into the welding chamber of the diffusion welding pressure device. S3. Start the vacuum device to evacuate the welding chamber; S4. Apply current to the water-cooled plate through the electrodes to form a closed current loop; use the Joule heat generated by the current at the interface to be welded to raise the temperature of the interface to be welded to the diffusion welding temperature, while controlling the temperature of the non-welding area of ​​the water-cooled plate to not exceed 500℃. S5. When the interface to be welded reaches the diffusion welding temperature, apply a preset pressure to the water-cooled plate and maintain the temperature and pressure for a preset time. S6. After the heat preservation and pressure holding are completed, stop heating and release the pressure; after cooling, the welded water-cooled plate body is obtained.

[0007] As an optional technical solution for welding water-cooled plates, the material of the water-cooled plate is aluminum alloy; after the surface pretreatment in step S1, the thickness of the residual oxide film at the interface to be welded on the water-cooled plate is 2nm-5nm, and the resistivity of the oxide film is ≤1×10⁻⁶. -4 With a thermal conductivity of ≤30W / (m·K) and Ω·m, the physical properties of the oxide film are utilized to achieve rapid heating and local heat preservation of the interface to be welded.

[0008] As an optional technical solution for welding water-cooled pan bodies, the surface pretreatment step of the water-cooled pan body in step S1 further includes: S11. The water-cooled plate is sequentially washed with water, degreased, acid-etched, acid-washed, and ultrasonically cleaned with acetone. After cleaning, it is dried. S12. After drying, wipe the interface to be soldered with anhydrous ethanol and let it air dry to obtain the interface to be soldered. The surface roughness Ra of the interface to be soldered is ≤0.8μm.

[0009] As an optional technical solution for welding water-cooled plates, in step S3, the vacuum device includes a molecular pump; after evacuation, the vacuum degree in the welding chamber is ≤1×10⁻⁶. -3 Pa, the vacuum environment inside the welding chamber is configured to prevent secondary oxidation of the interface to be welded during the heating process.

[0010] As an optional technical solution for welding a water-cooled plate, in step S4, the closed current loop is composed of a power supply, an upper electrode, a lower electrode, a diffusion welding fixture, and the water-cooled plate; the upper electrode and the lower electrode are in close contact with the water-cooled plate, and the contact gap is ≤0.1mm.

[0011] As an optional welding method for water-cooled plates, both the upper and lower electrodes are made of conductive graphite, and the resistivity of the conductive graphite is ≤1×10⁻⁶. -5 Ω・m, the high temperature resistance of conductive graphite is ≥800℃.

[0012] As an optional technical solution for welding a water-cooled plate, in step S4, the diffusion welding temperature is 530℃-580℃, and the temperature of the interface to be welded is monitored in real time by inserting a thermocouple into a preset temperature measuring hole; the temperature of the non-welding area is 400℃-500℃. The current in the closed current loop is dynamically adjusted based on the temperature of the interface to be welded, so as to achieve precise control of the temperature of the interface to be welded and temperature suppression in the non-welding area.

[0013] As an optional technical solution for welding water-cooled plate bodies, the preset pressure in step S5 is 1.5MPa-3MPa. The preset pressure is applied vertically to the area to be welded of the water-cooled plate body through the upper and lower pressure heads of the diffusion welding pressure device.

[0014] As an optional technical solution for welding water-cooled plate bodies, in step S5, the preset time for heat preservation and pressure preservation is 240min-360min.

[0015] As an optional technical solution for welding a water-cooled plate, in step S6, the overall deformation of the water-cooled plate after welding is no more than 0.1 mm, and the shrinkage rate of the cross-sectional area of ​​the cooling channel is no more than 5%.

[0016] The beneficial effects of the present invention include at least the following: This invention provides a welding method for a water-cooled plate, which mainly includes the following steps: S1. Pre-treating the surface of the water-cooled plate to remove the oxide film on the surface of the water-cooled plate and the interface to be welded. S2. Placing the water-cooled plate after the pre-treatment in S1 into the welding chamber of a diffusion welding pressure device. S3. Activating the vacuum device to evacuate the welding chamber. S4. Applying current to the water-cooled plate through electrodes to form a closed current loop; utilizing the Joule heat generated by the current at the interface to be welded to raise the temperature of the interface to be welded to the diffusion welding temperature, while controlling the temperature of the non-welding area of ​​the water-cooled plate to not exceed 500°C. S5. After the interface to be welded reaches the diffusion welding temperature, applying a preset pressure to the water-cooled plate and maintaining the temperature and pressure for a preset time. S6. After the temperature and pressure maintenance is completed, stopping heating and releasing the pressure; after cooling, the welded water-cooled plate is obtained.

[0017] Traditional welding methods require heating the entire water-cooled plate to the welding temperature, resulting in excessive overall heat input, concentrated thermal stress, and significant deformation of the water-cooled plate. Furthermore, the cooling channels soften at high temperatures and are prone to collapse. The welding method for the water-cooled plate in this invention creates a closed loop by applying current to the water-cooled plate. This current concentrates Joule heat at the welding interface, ensuring that the welding heat acts only on the area to be welded. Simultaneously, the temperature of the non-welding area is strictly controlled to not exceed 500°C. This significantly reduces the overall heat input of the water-cooled plate, minimizes the generation and accumulation of thermal stress, effectively suppresses overall deformation and collapse of the internal cooling channels, ensures the structural integrity of the water-cooled plate, and guarantees its effective cooling performance for the wafer. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0019] Figure 1 This is a schematic flowchart of the welding method for the water-cooled plate body provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0022] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0023] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] In this invention, unless otherwise explicitly 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 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 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.

[0026] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] This embodiment provides a welding method for a water-cooled plate, which can reduce the deformation of the water-cooled plate and the collapse of the cooling channels after welding, thus ensuring the cooling effect of the water-cooled plate on the wafer.

[0029] like Figure 1 As shown, the welding method for this water-cooled plate mainly includes the following steps: S1. Perform surface pretreatment on the water-cooled plate to remove the oxide film on the surface of the water-cooled plate and the interface to be welded. S2. The water-cooled plate body, which has been pretreated by S1, is installed into the welding chamber of the diffusion welding pressure device. S3. Start the vacuum device to evacuate the welding chamber; S4. Apply current to the water-cooled plate through the electrodes to form a closed current loop; use the Joule heat generated by the current at the interface to be welded to raise the temperature of the interface to be welded to the diffusion welding temperature, while controlling the temperature of the non-welding area of ​​the water-cooled plate to not exceed 500℃. S5. When the interface to be welded reaches the diffusion welding temperature, apply a preset pressure to the water-cooled plate and maintain the temperature and pressure for a preset time. S6. After the heat preservation and pressure holding are completed, stop heating and release the pressure; after cooling, the welded water-cooled plate body is obtained.

[0030] Traditional welding methods require heating the entire water-cooled plate to the welding temperature, resulting in excessive heat input to the component. This leads to thermal stress concentration and significant deformation of the water-cooled plate. Furthermore, the cooling channels are prone to collapse due to softening at high temperatures.

[0031] Based on the above design, in this embodiment, the method forms a closed loop by applying current to the water-cooled plate, and uses the current to generate Joule heat at the interface to be soldered, so that the welding heat only acts on the area to be soldered. At the same time, the temperature of the non-soldering area is strictly controlled not to exceed 500°C, which greatly reduces the overall heat input of the water-cooled plate, reduces the generation and accumulation of thermal stress, effectively suppresses the overall deformation of the water-cooled plate and the collapse of the internal cooling channels, ensures the structural integrity of the water-cooled plate, and ensures the cooling effect of the water-cooled plate on the wafer.

[0032] Specifically, in this embodiment, the water-cooling plate is made of aluminum alloy; after surface pretreatment in step S1, the thickness of the residual oxide film at the interface to be soldered on the water-cooling plate is 2nm-5nm, and the resistivity of the oxide film is ≤1×10⁻⁶. -4 With a thermal conductivity of ≤30W / (m·K) and Ω·m, the physical properties of the oxide film are utilized to achieve rapid heating and local heat preservation of the interface to be welded.

[0033] Aluminum alloys, commonly used in water-cooled trays for semiconductor devices, are prone to oxidation, resulting in a residual 2nm-5nm limiting oxide film even after pretreatment. The low resistivity of this oxide film allows for rapid Joule heating when current passes through it. Furthermore, the low thermal conductivity of this oxide film reduces heat conduction to non-welding areas, creating a thermal resistance effect that prolongs the high-temperature holding time at the welding interface, promoting sufficient atomic diffusion. This characteristic, combined with current-assisted heating, further shortens heating time and reduces energy consumption, while preventing overheating of non-welding areas due to heat conduction. This achieves precise temperature control—rapid heating of the interface to be welded and low-temperature holding of non-welding areas—avoiding the drawbacks of traditional techniques that require overall heating to reach the welding temperature.

[0034] In this embodiment, step S1, which involves surface pretreatment of the water-cooled plate, further includes: S11. The water-cooled plate is sequentially washed with water, degreased, acid-etched, acid-washed, and ultrasonically cleaned with acetone. After cleaning, it is dried.

[0035] Specifically, the water-cooling plate is first rinsed with deionized water to remove surface dust; then it is immersed in a 5% alkaline degreasing agent (a mixture of sodium hydroxide and sodium carbonate) at 60°C for 10 minutes to remove surface oil; after rinsing with deionized water, it is then immersed in a 10% hydrofluoric acid solution for 30 seconds to remove impurities from the outer layer of the oxide film; next, it is placed in a 15% nitric acid solution for 2 minutes to neutralize residual acid and refine the surface; then, the water-cooling plate is placed in an acetone solution and ultrasonically cleaned (200W power, 40kHz frequency) for 15 minutes to thoroughly remove residual contaminants in the micro-crevices; finally, the cleaned water-cooling plate is placed in an oven and dried at 80°C for 2 hours to obtain a pre-treated water-cooling plate with no obvious impurities on the surface.

[0036] S12. After drying, wipe the interface to be soldered with anhydrous ethanol and let it air dry to obtain the interface to be soldered. The surface roughness Ra of the interface to be soldered is ≤0.8μm.

[0037] Specifically, a lint-free cloth was moistened with anhydrous ethanol and gently wiped across the soldering interface of the disk. After air drying, the surface roughness Ra of the soldering interface was measured using a roughness tester, showing a clean and bright appearance. For example, the residual oxide film thickness at the soldering interface was measured to be 3 nm, with a resistivity of 5 × 10⁻⁶. -5 Ω・m, thermal conductivity is 25W / (m・K).

[0038] In step S3, the vacuum device includes a molecular pump; after evacuation, the vacuum level inside the welding chamber is ≤1×10⁻⁶. -3 Pa, the vacuum environment inside the welding chamber is configured to prevent secondary oxidation of the interface to be welded during the heating process.

[0039] Specifically, aluminum alloys oxidize very easily at high temperatures. If air is present in the welding environment, a new oxide film will quickly form at the welding interface. This oxide film hinders atomic diffusion, leading to a decrease in weld joint strength and an increase in defects. In this embodiment, a molecular pump is used to evacuate the vacuum to 1×10⁻⁶. -3 Pa completely isolates oxygen, and the interface to be welded does not undergo secondary oxidation at a high temperature of 550℃. The weld joint is free of oxide inclusions, ensuring sufficient metallurgical bonding and further guaranteeing the long-term stability of the water cooling plate.

[0040] In step S4, the closed current loop is composed of a power supply, an upper electrode, a lower electrode, a diffusion welding fixture, and a water-cooled plate; the upper electrode and the lower electrode are in close contact with the water-cooled plate, and the contact gap is ≤0.1mm.

[0041] When the bonding gap is greater than 0.1mm, the contact resistance increases exponentially, resulting in arc discharge at the interface instead of uniform Joule heating, causing local ablation; at the same time, it avoids the phenomenon of local temperature runaway caused by additional heat generation at the contact point.

[0042] For example, both the upper and lower electrodes are made of conductive graphite, and the resistivity of the conductive graphite is ≤1×10⁻⁶. -5 Ω・m, the high temperature resistance of conductive graphite is ≥800℃.

[0043] Low resistivity of conductive graphite (≤1×10⁻⁶) -5 The conductivity (Ω・m) ensures minimal electrode loss and heat generation during current flow, preventing the upper and / or lower electrode heating from affecting the water-cooled plate temperature control. The high-temperature resistance (≥800℃) of conductive graphite ensures stable performance at 550℃ at the welding interface, without softening, deformation, or oxidation, guaranteeing the stability of the current loop during welding. Compared to traditional metal electrodes (such as copper electrodes, with high temperature resistance ≤600℃ and higher resistivity), the upper and lower electrodes of conductive graphite effectively avoid welding quality fluctuations caused by upper and lower electrode wear, improving process repeatability and extending service life.

[0044] In step S4, the diffusion welding temperature is 530℃-580℃, and the temperature of the interface to be welded is monitored in real time by inserting a thermocouple into a preset temperature measuring hole; the temperature of the non-welding area is 400℃-500℃. The current in the closed current loop is dynamically adjusted based on the temperature of the interface to be welded to achieve precise control of the temperature of the interface to be welded and temperature suppression of the non-welding area.

[0045] 530℃-580℃ is the optimal temperature range for diffusion welding of aluminum alloys, which can ensure sufficient atomic diffusion without causing excessive softening of the aluminum alloy; the temperature of 400℃-500℃ in the non-welding area can not only avoid the formation of diffusion weld joints due to excessively low temperature, but also avoid deformation of the water cooling plate due to excessively high temperature.

[0046] In some optional embodiments, the thermocouple real-time monitoring feedback cycle is 1 second, and the control system adopts a PID algorithm. When the welding interface temperature is below 530℃, the current increases at a rate of 50A / s; when the welding interface temperature is above 580℃, the current decreases at a rate of 100A / s. Through the above dynamic adjustment, the welding interface temperature fluctuation can be controlled within ±5℃, avoiding insufficient diffusion due to excessively low temperature or grain coarsening due to excessively high temperature. At the same time, the temperature of the non-welding area of ​​the water-cooled plate is controlled between 400℃ and 500℃. When the temperature of the non-welding area is below 400℃, the excessive rigidity of the water-cooled plate will hinder the creep deformation of the welding interface, which is not conducive to the closure of the diffusion weld. When the temperature of the non-welding area is above 500℃, the strength of the cooling channel support structure decreases, and collapse is likely to occur.

[0047] The preset pressure in step S5 is 1.5MPa-3MPa. The preset pressure is applied vertically to the area to be welded on the water-cooled plate by the upper and lower pressure heads of the diffusion welding pressure device.

[0048] A pressure range of 1.5-3 MPa is the optimal pressure range for diffusion welding of aluminum alloys: if the preset pressure is too low (<1.5 MPa), the contact between the interfaces to be welded will be insufficient, and atomic diffusion will be hindered; if the preset pressure is too high (>3 MPa), it will exacerbate the collapse of the cooling channels. For example, in this embodiment, a pressure of 2 MPa is applied, which can promote atomic diffusion at the interfaces to be welded while avoiding excessive pressure that will compress the cooling channels.

[0049] In step S5, the preset holding time for heat preservation and pressure holding is 240-360 minutes. The core of diffusion welding is the formation of metallurgical bonding through atomic diffusion. If the holding time is too short (<240 minutes), atomic diffusion will be insufficient, resulting in insufficient weld joint strength; if the holding time is too long (>360 minutes), energy consumption will increase, and excessive grain growth may occur at the interface to be welded, affecting the toughness of the weld joint. In this embodiment, the holding time for heat preservation and pressure holding can be set to 300 minutes, so that the atomic diffusion depth at the interface to be welded reaches more than 5 μm, the tensile strength of the weld joint reaches 280 MPa, and excessive grain growth is avoided, ensuring that the weld joint has both strength and toughness.

[0050] In step S6, the overall deformation of the water-cooled plate after welding is no more than 0.1 mm, and the shrinkage rate of the cooling channel cross-sectional area is no more than 5%. For example, in this embodiment, the deformation of the water-cooled plate after welding is 0.08 mm, and the shrinkage rate of the cooling channel cross-sectional area is 3%. This not only ensures that the water-cooled plate and the wafer are tightly fitted, improving heat transfer efficiency, but also ensures that the cooling channel has low flow resistance to the cooling medium, guaranteeing the cooling rate and cooling uniformity.

[0051] Obviously, the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

[0052] Note that in the description of this specification, the references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A welding method for a water-cooled plate body, characterized in that, include: S1. Perform surface pretreatment on the water-cooled plate to remove the oxide film on the surface of the water-cooled plate and the interface to be welded. S2. The water-cooled plate body, which has been pretreated by S1, is installed into the welding chamber of the diffusion welding pressure device. S3. Start the vacuum device to evacuate the welding chamber; S4. Apply current to the water-cooled plate through the electrodes to form a closed current loop; use the Joule heat generated by the current at the interface to be welded to raise the temperature of the interface to be welded to the diffusion welding temperature, while controlling the temperature of the non-welding area of ​​the water-cooled plate to not exceed 500℃. S5. When the interface to be welded reaches the diffusion welding temperature, apply a preset pressure to the water-cooled plate and maintain the temperature and pressure for a preset time. S6. After the heat preservation and pressure holding are completed, stop heating and release the pressure; after cooling, the welded water-cooled plate body is obtained.

2. The welding method for the water-cooled plate body according to claim 1, characterized in that, The water-cooling plate is made of aluminum alloy; after surface pretreatment in step S1, the thickness of the residual oxide film at the interface to be soldered on the water-cooling plate is 2nm-5nm, and the resistivity of the oxide film is ≤1×10⁻⁶. -4 With a thermal conductivity of ≤30W / (m·K) and Ω·m, the physical properties of the oxide film are utilized to achieve rapid heating and local heat preservation of the interface to be welded.

3. The welding method for the water-cooled plate body according to claim 1, characterized in that, The surface pretreatment step of the water-cooled plate in step S1 also includes: S11. The water-cooled plate is sequentially washed with water, degreased, acid-etched, acid-washed, and ultrasonically cleaned with acetone. After cleaning, it is dried. S12. After drying, wipe the interface to be soldered with anhydrous ethanol and let it air dry to obtain the interface to be soldered. The surface roughness Ra of the interface to be soldered is ≤0.8μm.

4. The welding method for the water-cooled plate body according to claim 1, characterized in that, In step S3, the vacuum device includes a molecular pump; after evacuation, the vacuum level inside the welding chamber is ≤1×10⁻⁶. -3 Pa, the vacuum environment inside the welding chamber is configured to prevent secondary oxidation of the interface to be welded during the heating process.

5. The welding method for the water-cooled plate body according to claim 1, characterized in that, In step S4, the closed current loop is composed of a power supply, an upper electrode, a lower electrode, a diffusion welding fixture, and a water-cooled plate; the upper electrode and the lower electrode are in close contact with the water-cooled plate, and the contact gap is ≤0.1mm.

6. The welding method for the water-cooled plate body according to claim 5, characterized in that, Both the upper and lower electrodes are made of conductive graphite, and the resistivity of the conductive graphite is ≤1×10⁻⁶. -5 Ω・m, the high temperature resistance of conductive graphite is ≥800℃.

7. The welding method for the water-cooled plate body according to claim 1, characterized in that, In step S4, the diffusion welding temperature is 530℃-580℃, and the temperature of the interface to be welded is monitored in real time by inserting a thermocouple into a preset temperature measuring hole; the temperature of the non-welding area is 400℃-500℃. The current in the closed current loop is dynamically adjusted based on the temperature of the interface to be welded, so as to achieve precise control of the temperature of the interface to be welded and temperature suppression in the non-welding area.

8. The welding method for the water-cooled plate body according to claim 1, characterized in that, The preset pressure in step S5 is 1.5MPa-3MPa. The preset pressure is applied vertically to the area to be welded on the water-cooled plate by the upper and lower pressure heads of the diffusion welding pressure device.

9. The welding method for the water-cooled plate body according to claim 1, characterized in that, In step S5, the preset time for heat preservation and pressure preservation is 240min-360min.

10. The welding method for the water-cooled plate body according to claim 1, characterized in that, In step S6, the overall deformation of the water-cooled plate after welding is no more than 0.1 mm, and the shrinkage rate of the cross-sectional area of ​​the cooling channel is no more than 5%.

Images