Waterway back plate for planar target material and preparation method and application of waterway back plate

Abstract

The invention provides a waterway backboard for a planar target material and a preparation method and application thereof, and belongs to the technical field of target materials. The waterway back plate for the plane target material is composed of a base body and a flow channel located on the base body, the flow channel and the base body are integrally formed, the flow channel is provided with a first opening and a second opening which are located in the base body, the flow channel comprises a straight flow channel and an S-shaped flow channel, one end of the straight flow channel is connected with the first opening, and the other end of the straight flow channel is connected with the S-shaped flow channel. And the other end of the S-shaped runner is connected with the second opening. The preparation method comprises the steps of material selection, 3D printing, hot isostatic pressing treatment, high-temperature aging, polishing and the like. The compactness of the waterway backboard for the plane target material is larger than or equal to 99.9%, the heat conductivity is larger than or equal to 350 W / (m.k), and the target material deformation / cracking phenomenon caused by temperature difference can be effectively reduced.

Description

Technical Field

[0001] This invention belongs to the field of target technology and relates to a method for preparing a planar target with a water channel backplate and its application. Background Technology

[0002] Sputtering targets are functional materials that are sputtered and deposited onto a substrate to form a thin film by bombarding the target surface with a high-energy ion beam in a high-vacuum environment using magnetron sputtering technology. They are categorized by application field, such as semiconductor chip targets, flat panel display targets, and photovoltaic targets. As a core component in PVD (Physical Vapor Deposition) processes such as magnetron sputtering and ion plating, the heat dissipation performance and structural stability of the flat panel target directly affect the coating uniformity and target lifespan. During magnetron sputtering, the kinetic energy is converted into heat energy due to the continuous bombardment by high-speed particles, causing the target to accumulate a large amount of heat. To prevent the target from overheating and causing de-targeting, the overall temperature of the target must be maintained within a certain range, requiring a backplate with water channels to cool the target.

[0003] The water-cooled backplate achieves active thermal management of the target material through internal cooling channels. It must meet three core requirements: high thermal conductivity, structural strength, and precision forming of complex channels. At the same time, it provides mechanical support to prevent brittle target materials such as ceramics and brittle alloys from cracking or deforming due to thermal stress during sputtering.

[0004] The industry currently faces the following technical bottlenecks: 1. Existing copper / aluminum backplates mostly employ drilling + sealing welding processes to manufacture flow channels, resulting in problems such as a single flow channel shape (only straight lines / simple bends) and uneven flow resistance distribution. Experimental data shows that the cooling efficiency difference of traditional parallel flow channels can reach 30%, leading to an increased target surface temperature gradient, inducing uneven coating thickness (±15% deviation) and the risk of target material cracking. 2. Under high-power sputtering environments (≥10kW), pure copper backplates, due to their coefficient of thermal expansion (17×10⁻⁶), -6 / ℃) and ceramic target material (6-8×10 -6 The mismatch ( / ℃) and the existing copper / aluminum backplates have a high diffusion welding defect rate of up to 12%, which will cause temperature differences in the target material during sputtering, and easily lead to interfacial thermal stress cracks.

[0005] In traditional water channel backplate designs in this field, the water tank plate and the cover plate are connected by positioning posts. Such a water channel backplate connection is unstable, and the cover plate may fall off.

[0006] Chinese invention application CN112045309A discloses a method for preparing a water channel backplate for a target material. The method involves: (1) machining a T-groove on a copper backplate body, the T-groove including a cover plate groove and a water groove arranged from top to bottom; (2) placing a cover plate on the cover plate groove to obtain the copper backplate to be welded; (3) fixing the workpiece to be welded on a rigid fixture; (4) placing a laser above the copper backplate to be welded; (5) spot welding the copper backplate to be welded; (6) performing a first welding; and (7) performing a second welding. This method completes the preparation through welding. The core function of the water channel backplate is circulating cooling water, therefore, the complete sealing of the weld is crucial. However, during welding, gas often fails to escape from the molten pool in time (e.g., insufficient protective gas, oil stains or moisture residue on the base material surface), leading to cooling water leakage, reduced heat dissipation efficiency, and potential long-term corrosion. Welding defects in the water channel backplate significantly increase the cost of a single molybdenum target, while uneven cooling leads to a higher frequency of target replacements, which reduces the annual effective capacity of the equipment.

[0007] Chinese invention application CN119634752A discloses a heat treatment method for improving the mechanical properties of GH4099 high-temperature alloy. The method includes: first, using laser additive manufacturing to print GH4099 alloy material into parts; then, sequentially performing annealing, hot isostatic pressing, solution treatment, and aging treatment on the parts. This method can eliminate voids in the parts and increase density; simultaneously, it promotes grain recrystallization, altering the original columnar crystal morphology and eliminating anisotropy in the material's mechanical properties. However, this method is mainly used for materials used in aero-engines and involves extremely high processing temperatures (solution treatment temperature of 1140℃), which may not be applicable to metals with lower melting points or everyday metal utensils.

[0008] Therefore, there is an urgent need to develop new backplane technologies that combine high thermal conductivity, low thermal stress, and optimized flow channels to support the high-precision coating requirements of semiconductor, photovoltaic and other fields. Summary of the Invention

[0009] In view of this, and considering that existing technologies cannot provide a novel backplate that balances high thermal conductivity, low thermal stress, and optimized flow channels, the purpose of this invention is to provide a planar target material water channel backplate, its preparation method, and its application.

[0010] To achieve the above-mentioned objective, a first aspect of the present invention provides a method for preparing a planar target material with a water channel backplate, comprising the steps of: S1. Material selection: Copper powder is used as the raw material; S2, 3D printing: The water channel backplate is formed by 3D printing. After printing, it is annealed in situ and then cooled to room temperature. S3, hot isostatic pressing (HIP) treatment, then cooled to room temperature; S4, high-temperature aging and annealing; S5. Fluid polishing to obtain a planar target material with a water channel backplate.

[0011] Further, in step S1, the copper powder is spherical copper powder with a purity ≥99.95%, a particle size of 100-300 mesh, a flowability of 18-30s / 50g, and an oxygen content ≤100ppm.

[0012] Furthermore, in step S2, the 3D printing is interlayer rotational scanning printing, performed under a protective gas atmosphere.

[0013] In one specific embodiment of the present invention, the protective gas is N2.

[0014] Furthermore, in step S2, the interlayer rotational scanning printing specifically involves: rotating each layer by 67°, an interlayer scanning speed ≤ 600 mm / s, and a laser energy density of 120-200 J / mm². 3 Single scan thickness ≤ 0.05mm, substrate temperature 250℃-300℃.

[0015] Furthermore, in step S2, during the interlayer rotational scanning printing, the scanning speed at the contours and edges is ≤400mm / s.

[0016] Further, in step S2, the in-situ annealing treatment specifically involves an annealing temperature of 300-350℃ and a time of 4-6 hours; the cooling to room temperature specifically involves cooling to room temperature at a rate of 1℃ / min-5℃ / min.

[0017] Further, in step S3, the hot isostatic pressing treatment specifically involves a treatment time of 1-4 hours at a temperature of 500-600℃ and a pressure of 160-200 MPa.

[0018] Furthermore, in step S4, the high-temperature aging treatment specifically involves treating at 600-750℃ for 10-24 hours under an inert gas atmosphere or high vacuum conditions.

[0019] Furthermore, in step S5, the polishing is to polish the flow channel, and the polishing is to first perform rough polishing and then fine polishing.

[0020] Furthermore, in step S5, the main material for coarse polishing is powder with a Mohs hardness greater than 8.5, the particle size of the powder is 80-120 mesh, the solid phase mass content of the fluid for coarse polishing is 25%-55%, and the viscosity is 15000-30000 Cp.

[0021] Furthermore, in step S5, the main material for fine polishing is a powder with a Mohs hardness greater than 8.5, the particle size of the powder is 2000-4000 mesh, the solid phase mass content of the fine polishing fluid is 20%-40%, and the viscosity is 8000-12000 Cp.

[0022] Furthermore, the powder with a Mohs hardness greater than 8.5 can be diamond powder, green silicon carbide powder, or alumina powder.

[0023] More preferably, the Mohs hardness ranges from 8.5 to 10. Any point value or range value within the range of 8.5 to 10, including the endpoint value, can achieve the technical effect described in this application.

[0024] Furthermore, in step S5, the parameters for coarse polishing are: injection pressure 3-8 MPa, flow rate 3 L / min-5 L / min, and number of cycles 15-25; the parameters for fine polishing are: injection pressure 4-6 MPa, flow rate 5 L / min-10 L / min, and number of cycles 10-20.

[0025] Preferably, step S5 further includes CNC precision machining and tapping steps.

[0026] In a second aspect, the present invention provides a planar target material water channel backplate, the planar target material water channel backplate being composed of a substrate (1) and a flow channel (2) therein, the flow channel (2) being integrally formed with the substrate (1), the flow channel (2) having a first opening (3) and a second opening (4) located on the substrate (1), the flow channel (2) including a straight flow channel (5) and an S-shaped flow channel (6), one end of the straight flow channel (5) being connected to the first opening (3) and the other end being connected to the S-shaped flow channel (6), the other end of the S-shaped flow channel (6) being connected to the second opening (4). The flow channel (2) is an internal flow channel.

[0027] Furthermore, the straight flow channel (5) extends between the center of the substrate (1) and the edge of the substrate (1), forming a first opening (3) at the edge of the substrate (1); the S-shaped flow channel (6) starts from the center of the substrate (1) of the straight flow channel (5), extends in an arc shape to the vicinity of the straight flow channel (5), then reverses and extends back along the outer edge of the aforementioned extension, extends again to the vicinity of the straight flow channel (5), and then reverses and extends back again, repeatedly reversing and extending until the edge of the substrate (1), forming a second opening (4).

[0028] A third aspect of the present invention provides the use of the above-mentioned planar target material with a water channel backplate in PVD process products, ceramic flat target materials, and hard and brittle metal and alloy planar target materials.

[0029] Preferably, the ceramic plate target material includes: aluminum-doped zinc oxide (AZO) target material, ITO target material, and indium gallium zinc oxide (IGZO) target material.

[0030] Preferably, the alloy planar target material includes: a target material containing W, Mo, WTi (tungsten titanium), or WSi (tungsten silicon).

[0031] Compared with the prior art, the present invention has the following beneficial effects: (1) The flow channels of the waterway backplate include direct-flow and topology-optimized S-shaped flow channels; the topology-optimized S-shaped flow channels and Figure 2 Compared with traditional water channel backplates, it can reduce water pressure by more than 63% and improve temperature uniformity by more than 50%, effectively reducing the deformation / cracking of the target material caused by temperature difference.

[0032] (2) The water channel backplate is integrally formed using 3D printing technology. Firstly, it can completely avoid defects such as flow channel misalignment, deformation, and poor welding caused by traditional diffusion welding methods; secondly, it can avoid high leakage rates caused by poor welding; thirdly, it can avoid high water pressure, uneven water flow, and reduced heat dissipation capacity caused by welding misalignment; and finally, it can avoid shear strength attenuation caused by long-term thermal cycling of the brazing interface, with attenuation being almost zero, while existing technologies such as Figure 2 The shear strength of traditional waterway backplates can decrease by more than 60%, improving the reliability for long-term use.

[0033] (3) HIP technology is used to eliminate microscopic defects generated in the 3D printing process, optimize the grain size of the product, form an equiaxed crystal structure, and increase the density of the product to over 99.9% and the thermal conductivity to over 300 W / (mk). Then, by annealing and recrystallizing the HIP product, the thermal conductivity of the product can be increased to over 350 W / (mk), further improving the performance of the product.

[0034] (4) The flow channel is polished by using fluid polishing technology to remove the powder adhering to the inner wall of the flow channel and make the inner wall present a near mirror appearance; effectively reducing the resistance of water flow. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the integrated waterway backplate of Example 1.

[0036] Among them, 1. Matrix; 2. Flow channel; 3. First opening; 4. Second opening; 5. Straight flow channel; 6. S-shaped flow channel.

[0037] Figure 2 This is a schematic diagram of a traditional waterway backplate.

[0038] Among them, 1 is the water tank plate; 2 is the cover plate; and 3 is the positioning column. Detailed Implementation

[0039] Terminology and Declarations of this Invention: 1. Articles “a,” “a kind,” and “the”: These include plural objects unless otherwise explicitly specified as a single (kind) object.

[0040] 2. Numerical Range: Unless otherwise expressly stated, all ranges or ratios disclosed herein shall be construed as including any and all subranges or subratios contained herein. For example, a stated range or ratio of 1 to 30 shall be considered to be included between the minimum value of 1 and the maximum value of 30, and includes any subranges or subratios, integers, decimals, or subranges or subratios consisting of integers or decimals, including endpoints.

[0041] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0042] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention were obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process was carried out at room temperature.

[0043] In the following examples, some of the reagents were sourced from the following table: Table 1

[0044] Example 1 like Figure 1 As shown, the planar target material uses a water channel backplate consisting of a substrate 1 and flow channels 2 located thereon. The flow channels 2 are integrally formed with the substrate 1. The flow channels 2 have a first opening 3 and a second opening 4 located on the substrate 1. The flow channels 2 include a straight flow channel 5 and an S-shaped flow channel 6. The straight flow channel 5 extends between the center of the substrate 1 and the edge of the substrate 1, forming the first opening at the edge of the substrate 1. The S-shaped flow channel 6 starts from the center of the substrate 1 of the straight flow channel 5, extends in an arc shape to the vicinity of the straight flow channel 5, then reverses and extends back along the outer edge of the aforementioned extension. It extends again to the vicinity of the straight flow channel 5, then reverses and extends back again, repeatedly reversing and extending until it reaches the edge of the substrate, forming the second opening.

[0045] Fluid can flow from the first opening 3 through the straight flow channel 5 into the S-shaped flow channel 6, and then exit from the second opening 4; or it can enter the straight flow channel 5 from the second opening 4 through the S-shaped flow channel 6, and then exit from the first opening 3.

[0046] Among them, the S-shaped flow channel 6 is a topology-optimized S-shaped flow channel 6. The topology-optimized S-shaped structure flow channel 6 can reduce water pressure by more than 65% and improve temperature uniformity by more than 50%, effectively reducing the deformation / cracking of the target material caused by temperature difference.

[0047] Example 2 The planar target material with a water channel backplate as shown in Example 1 was prepared according to the following steps: S1. Material Selection: Select spherical copper powder with a purity of ≥99.95%, a particle size of 200-250 mesh, a flowability of 20s / 50g, and an oxygen content of ≤100ppm as raw material.

[0048] S2, 3D Printing: The topology-optimized water channel backplate is formed using 3D printing according to the flow channel shape of Example 1; the 3D printing employs an interlayer rotational scanning strategy, rotating 67° per layer; the interlayer scanning speed is 600 mm / s, and the contour and edge scanning speed is 400 mm / s; the laser energy density is 150 J / mm². 3 The single-scan thickness was 0.05 mm, with full N2 protection and a substrate temperature of 270℃. After printing, in-situ annealing was performed inside the cavity to eliminate thermal stress at a temperature of 320℃ for 5 hours. After annealing, the temperature was lowered to room temperature at a rate of 3℃ / min before the printed part was removed. The resulting printed part had a density of 98% and a thermal conductivity of 202 W / (mK).

[0049] S3. The printed part obtained in step S2 does not need to be coated. It is directly placed into a hot isostatic pressing (HIP) chamber for heat treatment. The HIP parameters are as follows: heating temperature 550℃, pressure 180MPa, and time 3h. After cooling to room temperature in the furnace, the product is removed. The product has a density of up to 99.9%, a thermal conductivity of 309W / (mk), and equiaxed grains.

[0050] S4, at 700℃ in an inert gas or high vacuum (0.5×10⁻⁶). -2 After annealing at high temperature for 20 hours, the product was removed after furnace cooling. The crystal form of the product did not change after annealing, and the thermal conductivity increased further. The grain size increased by more than 50%.

[0051] S5. Polishing: First, rough polishing is performed using diamond powder with a Mohs hardness of 10. The particle size of the diamond powder used for rough polishing is 100 mesh, the solid content of the polishing fluid is 40%, and the viscosity is 20000 Cp. The rough polishing cycle is 20 times with an injection pressure of 5 MPa and a flow rate of 4 L / min. Then, fine polishing is performed using diamond powder with a Mohs hardness of 10. The particle size of the diamond powder used for fine polishing is 3000 mesh, the solid content of the fine polishing fluid is 30%, and the viscosity is 10000 Cp. The fine polishing parameters are as follows: the fine polishing cycle is 15 times with an injection pressure of 5 MPa and a flow rate of 7 L / min.

[0052] S6. After polishing, the product's shape is subjected to simple operations such as CNC precision machining and tapping to obtain the planar target material water channel backplate.

[0053] Example 3 The planar target material with a water channel backplate as shown in Example 1 was prepared according to the following steps: S1. Material Selection: Select spherical copper powder with a purity ≥99.95%, particle size 100-200 mesh, flowability 30s / 50g, and oxygen content ≤100ppm as raw material.

[0054] S2, 3D Printing: The topology-optimized water channel backplate is formed using 3D printing according to the flow channel shape of Example 1; the 3D printing employs an interlayer rotational scanning strategy, rotating 67° per layer; the interlayer scanning speed is 500 mm / s, and the contour and edge scanning speed is 300 mm / s; the laser energy density is 200 J / mm². 3 The single-scan thickness was 0.04 mm, with full N2 protection and a substrate temperature of 250℃. After printing, in-situ annealing was performed inside the cavity to eliminate thermal stress at a temperature of 300℃ for 6 hours. After annealing, the temperature was lowered to room temperature at a rate of 1℃ / min before the printed part was removed. The resulting printed part had a density of 98% and a thermal conductivity of 214 W / (mK).

[0055] S3. The printed part obtained in step S2 does not need to be coated. It is directly placed into a hot isostatic pressing (HIP) chamber for heat treatment. The HIP parameters are as follows: heating temperature 500℃, pressure 200MPa, and time 1h. After cooling to room temperature in the furnace, the product is removed. The product has a density of 99.9%, a thermal conductivity of 315 W / (mk), and equiaxed grains.

[0056] S4, at 600℃ in an inert gas or high vacuum (0.1×10⁻⁶). -2 After annealing at high temperature for 24 hours, the product was removed after furnace cooling. The crystal form of the product did not change after annealing, the thermal conductivity increased further, and the grain size increased by more than 50%.

[0057] S5. Polishing: First, coarse polishing is performed using green silicon carbide powder with a Mohs hardness of 9.5. The particle size of the green silicon carbide powder used for coarse polishing is 80 mesh, the solid content of the polishing fluid is between 55%, and the viscosity is 15000 Cp. Coarse polishing is performed 15 times with an injection pressure of 3 MPa and a flow rate of 5 L / min. Then, fine polishing is performed using diamond powder with a Mohs hardness of 9.5. The particle size of the diamond powder used for fine polishing is 2000 mesh, the solid content of the fine polishing fluid is 40%, and the viscosity is 8000 Cp. The fine polishing parameters are as follows: fine polishing is performed 10 times with an injection pressure of 4 MPa and a flow rate of 10 L / min.

[0058] S6. After polishing, the product's shape is subjected to simple operations such as CNC precision machining and tapping to obtain the planar target material water channel backplate.

[0059] Example 4 The planar target material with a water channel backplate as shown in Example 1 was prepared according to the following steps: S1. Material Selection: Select spherical copper powder with a purity of ≥99.95%, a particle size of 200-300 mesh, a flowability of 18s / 50g, and an oxygen content of ≤100ppm as raw material.

[0060] S2, 3D Printing: The topology-optimized water channel backplate is formed using 3D printing according to the flow channel shape of Example 1; the 3D printing adopts an interlayer rotational scanning strategy, rotating 67° per layer; the interlayer scanning speed is 200 mm / s, and the contour and edge scanning speed is 100 mm / s; the laser energy density is 120 J / mm². 3 The single-scan thickness was 0.02 mm, with full N2 protection and a substrate temperature of 300℃. After printing, in-situ annealing was performed inside the cavity to eliminate thermal stress at a temperature of 350℃ for 4 hours. After annealing, the temperature was lowered to room temperature at a rate of 5℃ / min before the printed part was removed. The resulting printed part had a density of 95% and a thermal conductivity of 187 W / (mK).

[0061] S3. The printed part obtained in step S2 does not need to be coated. It is directly placed into a hot isostatic pressing (HIP) chamber for heat treatment. The HIP parameters are as follows: heating temperature 600℃, pressure 160MPa, and time 4h. After cooling to room temperature in the furnace, the product is removed. The product has a density of up to 99.9%, a thermal conductivity of 306W / (mk), and equiaxed grains.

[0062] S4, at 750℃ and in an inert gas or high vacuum (0.05×10⁻⁶). -2 After annealing at high temperature for 10 hours, the product was removed after furnace cooling. The crystal form of the product did not change after annealing, and the thermal conductivity increased further. The grain size increased by more than 50%.

[0063] S5. Polishing: First, coarse polishing is performed using alumina powder with a Mohs hardness of 9.0. The particle size of the alumina powder used for coarse polishing is 120 mesh, the solid content of the polishing fluid is between 25%, and the viscosity is 30000 Cp. Coarse polishing is performed 25 times with an injection pressure of 8 MPa and a flow rate of 3 L / min. Then, fine polishing is performed using diamond powder with a Mohs hardness of 9.5. The particle size of the diamond powder used for fine polishing is 4000 mesh, the solid content of the fine polishing fluid is 20%, and the viscosity is 12000 Cp. The fine polishing parameters are as follows: fine polishing is performed 20 times with an injection pressure of 6 MPa and a flow rate of 5 L / min.

[0064] S6. After polishing, the product's shape is subjected to simple operations such as CNC precision machining and tapping to obtain the planar target material water channel backplate.

[0065] Comparative Example 1 Compared with Example 2, the only difference is that the particle size of the spherical copper powder in step S1 is 60 mesh, and all other aspects are the same.

[0066] Comparative Example 2 Compared with Example 2, the only difference is that the annealing temperature in step S2 is 250°C, and all other aspects are the same.

[0067] Comparative Example 3 Compared with Example 2, the only difference is that the temperature of hot isostatic pressing in step S3 is 400°C, and all other aspects are the same.

[0068] Comparative Example 4 Compared with Example 2, the only difference is that the high-temperature aging step S4 is not performed; all other steps are the same.

[0069] Comparative Example 5 like Figure 2 The diagram shown is a schematic of a conventional water channel backplate in this field. 1 represents the water tank plate, 2 the cover plate, and 3 the positioning post. The water tank plate 1 and the cover plate 2 are connected by the positioning post. Such a water channel backplate connection is unstable, and the cover plate may detach.

[0070] Example of effect The performance of the samples prepared in Examples 2-4 and Comparative Examples 1-4 was tested, and compared with the conventional planar target material with water channel backplate in Comparative Example 5. The results are shown in Table 2 below: Table 2

[0071] As shown in Table 2 above, the thermal conductivity of the samples in Examples 2-4 reaches over 350 W / (mk), which meets the requirements for a water channel backplate for planar targets, and represents a significant improvement compared to the comparative examples. Furthermore, the temperature uniformity of the samples in Examples 2-4 is significantly improved compared to Comparative Examples 1-5. In addition, this application utilizes 3D printing for a one-piece construction. Compared to traditional water channel backplates connected by positioning posts, the water channel backplate of this application has a more robust connection, a more uniform structure, and no obvious structural heterogeneity such as weld seams. Therefore, the water channel backplate of this application can improve long-term reliability compared to traditional water channel backplates.

[0072] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing a planar target material with a water channel backplate, characterized in that, Including the following steps: S1. Material selection: Copper powder is used as the raw material; S2, 3D printing: The water channel backplate is formed by 3D printing. After printing, it is annealed in situ and then cooled to room temperature. S3, hot isostatic pressing, then cooled to room temperature; S4, high-temperature aging and annealing; S5. Fluid polishing to obtain a planar target material with a water channel backplate.

2. The preparation method according to claim 1, characterized in that, In step S1, the copper powder is spherical copper powder with a purity ≥99.95%, a particle size of 100-300 mesh, a flowability of 18-30s / 50g, and an oxygen content ≤100ppm.

3. The preparation method according to claim 1, characterized in that, In step S2, the 3D printing is interlayer rotational scanning printing, performed in a protective gas atmosphere; the in-situ annealing treatment specifically involves an annealing temperature of 300-350℃ and a time of 4-6 hours; the cooling to room temperature specifically involves cooling to room temperature at a rate of 1℃ / min-5℃ / min.

4. The preparation method according to claim 3, characterized in that, In step S2, the interlayer rotational scanning printing specifically involves: rotating each layer by 67°, an interlayer scanning speed ≤ 600 mm / s, and a laser energy density of 120-200 J / mm². 3 The thickness of a single scan is ≤0.05mm, the substrate temperature is 250℃-300℃, and the scanning speed at the contour and edges is ≤400mm / s.

5. The preparation method according to claim 1, characterized in that, In step S3, the hot isostatic pressing treatment specifically involves processing at 500-600℃ and 160-200 MPa for 1-4 hours.

6. The preparation method according to claim 1, characterized in that, In step S4, the high-temperature aging process specifically involves treating the product at 600-750℃ for 10-24 hours under an inert gas atmosphere or high vacuum conditions.

7. The preparation method according to claim 1, characterized in that, In step S5, the polishing is performed on the flow channel; the polishing consists of rough polishing followed by fine polishing. The main material for rough polishing is powder with a Mohs hardness > 8.5 and a particle size of 80-120 mesh. The solid content of the fluid used for rough polishing is 25%-55%, and the viscosity is 15000-30000 Cp. The parameters for rough polishing are: injection pressure 3-8 MPa, flow rate 3 L / min-5 L / min, and number of cycles 15-25. The main material for fine polishing is powder with a Mohs hardness > 8.5 and a particle size of 2000-4000 mesh. The solid content of the fluid used for fine polishing is 20%-40%, and the viscosity is 8000-12000 Cp. The parameters for fine polishing are: injection pressure 4-6 MPa, flow rate 5 L / min-10 L / min, and number of cycles 10-20.

8. The preparation method according to claim 1, characterized in that, Step S5 also includes CNC precision machining and tapping steps.

9. The planar target material prepared by the preparation method according to any one of claims 1-8 has a water channel backplate, characterized in that, The planar target material water channel backplate is composed of a substrate (1) and a flow channel (2) located therein. The flow channel (2) is integrally formed with the substrate (1). The flow channel (2) has a first opening (3) and a second opening (4) located on the substrate (1). The flow channel (2) includes a straight flow channel (5) and an S-shaped flow channel (6). One end of the straight flow channel (5) is connected to the first opening (3), and the other end is connected to the S-shaped flow channel (6). The other end of the S-shaped flow channel (6) is connected to the second opening (4).

10. The use of a planar target material prepared by any one of claims 1-8 with a water channel backplate or the planar target material with a water channel backplate as described in claim 9 in PVD process products, ceramic flat plate targets, hard and brittle metal and alloy planar targets.

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