Electroplating device and method for preparing coppering supporting layer of replicated ultra-cold neutron conduit

Abstract

The invention discloses an electroplating device for preparing an electroplating copper supporting layer of a replicated ultra-cold neutron conduit, and belongs to the technical field of neutron optics and chemical electroplating. Comprising a transparent polypropylene electroplating bath main body, a three-dimensional distance adjusting mechanism, a large-area rectangular anode plate, an external filtering unit, an external magnetic driving pump, an external cylindrical filter and a multi-path controllable water inlet system, a pair of parallel guide slots extending in the vertical direction are formed in the two side walls, and the external filter unit is mounted in the transparent polypropylene electroplating bath main body in a manner of being vertically inserted along the guide slots; according to the method, electric field distribution and a fluid flow field in the electroplating process are accurately controlled, it is ensured that uniform and stable current density and solution mass transfer conditions are formed on the large-area cathode surface, the thickness uniformity and internal stress distribution uniformity of a plating layer are improved, and a foundation is laid for subsequent successful stripping, roll welding operation and the like.

Description

Technical Field

[0001] This invention belongs to the field of neutron optics and chemical electroplating technology, and in particular to an electroplating apparatus and method for preparing a copper support layer for a replica ultracold neutron conduit. Background Technology

[0002] In ultracold neutron conduits and similar high-precision coating fields, the hundreds-of-micrometers-thick copper mechanical support layer typically requires electrochemical electroplating technology for fabrication. Currently, there is a lack of dedicated equipment in this field, and researchers usually borrow general-purpose electroplating equipment designed for PCB electroplating or ordinary metal electroplating.

[0003] The existing technology is a traditional rectangular electroplating tank system for single-sided electroplating. A typical configuration includes: an electroplating tank; a soluble phosphor bronze anode plate located at the bottom or one side of the tank; a simple clamp suspended opposite the anode for fixing the glass substrate (cathode); and possibly equipped with a mechanical stirring or basic pump circulation system for agitating the electroplating solution.

[0004] The internal stress state of the electroplated layer is strongly dependent on the local current density, additive concentration, and mass transfer efficiency during deposition. In traditional devices, the single, fixed anode-cathode spacing prevents optimization of the electric field distribution, resulting in significant edge effects and a much higher current density at the workpiece edges compared to the central region. Simultaneously, simple stirring or circulation methods fail to create a uniform and stable flow field on the cathode surface, leading to differences in the plating solution composition (main salt concentration, additive concentration) and mass transfer rate across different regions. This dual inhomogeneity of the electric and flow fields causes the deposition reaction to proceed with different kinetic processes at different locations on the cathode panel, ultimately resulting in a macroscopically uneven distribution of internal stress. This uneven internal stress can cause microscopic warping or macroscopic deformation of the copper film after electroplating, making complete and flat peeling from the rigid glass substrate impossible. Summary of the Invention

[0005] The purpose of this invention is to provide an electroplating apparatus and method for preparing a copper support layer for a replica ultracold neutron conduit, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an electroplating apparatus for preparing a replica of an ultracold neutron conduit with an electroplated copper support layer, comprising a transparent polypropylene electroplating tank body, a three-dimensional adjustment mechanism, a large-area rectangular anode plate, an external filtration unit, an external magnetic drive pump, an external cylindrical filter, and a multi-channel controllable water inlet system. The transparent polypropylene electroplating tank body is a rigid, insulating, and corrosion-resistant transparent container, with a pair of parallel guide slots extending vertically on its two opposite side walls. The external filter unit is installed inside the transparent polypropylene electroplating tank body by vertical insertion along the guide slots, forming a dynamic seal with the tank body after insertion, and its position is fixed between the anode and cathode; the large-area rectangular anode plate... The electrode plate is located on one side of the main body of the transparent polypropylene electroplating tank, fixed by a conductive round tube bracket and connected to the positive terminal of a DC power supply. Its size is larger than the glass substrate to be plated. The three-dimensional adjustment mechanism is located above the main body of the transparent polypropylene electroplating tank, including a support rod and two integrated orthogonal precision lead screw slides. The inlet of the external magnetic drive pump is connected to the outlet of the main body of the transparent polypropylene electroplating tank through an acid-resistant water pipe, and the outlet is connected to the inlet of an external cylindrical filter. The outlet of the external cylindrical filter is connected to the inlet pipes on the left, right and bottom directions of the cathode side of the main body of the transparent polypropylene electroplating tank through branch pipes. Each inlet pipe is equipped with an independent control valve, forming a circulation system to achieve directional flow and multi-path uniform flow distribution.

[0007] The main body of the transparent polypropylene electroplating tank is made of transparent polypropylene material and has optical visibility to observe the internal electroplating process. The guide slot is a rectangular groove opened on the opposite side walls of the main body of the transparent polypropylene electroplating tank, which runs through the vertical direction and is used to guide the insertion path of the external filter unit and provide lateral restraint.

[0008] The external filter unit is a detachable independent module whose shape matches the guide slot, and is used to prevent the migration of anode mud and suspended particles generated by anode dissolution to the cathode area.

[0009] The three-dimensional adjustment mechanism is fixedly installed above the main body of the transparent polypropylene electroplating tank. Two mutually orthogonal precision lead screw slides are integrated on both sides, and the support rod is in the middle for connecting the external cathode clamp.

[0010] It also includes a standardized cathode clamp interface, which is the support rod of the three-dimensional adjustment mechanism. The external cathode clamp is placed on the support rod by a hook. The external cathode clamp is used to clamp a flat glass substrate pre-coated with a Ni / Ti super mirror and a Cu seed layer.

[0011] The multi-channel controllable water inlet system includes three inlet pipes located on the cathode side of the main body of the transparent polypropylene electroplating tank, on the left, right and bottom sides respectively. Each inlet pipe is connected to a branch pipe from the outlet of the external cartridge filter and is equipped with an independent manual or electric valve.

[0012] The circulation system consists of an external magnetic drive pump, an acid-resistant water pipe, an external cylindrical filter, and branch pipes. The inlet of the external magnetic drive pump is connected to the outlet of the transparent polypropylene electroplating tank body through the acid-resistant water pipe, and the outlet is connected to the inlet of the external cylindrical filter.

[0013] A chemical electroplating operation method for an electroplating apparatus for preparing a replica of an ultracold neutron conduit with an electroplated copper support layer includes the following steps: S1: Insert the external filter unit vertically into the guide slot along the side wall of the transparent polypropylene electroplating tank until it is sealed in place, so that it is located between the large rectangular anode plate and the cathode area. S2: Install the external cathode fixture holding the glass substrate to be coated onto the support rod of the three-dimensional adjustment mechanism, and connect the power cord to the negative terminal of the external power supply; S3: By adjusting the Y-axis handwheel and translation support rod of the three-dimensional adjustment mechanism, the center of the cathode workpiece is aligned with the center of the large-area rectangular anode plate; rotate the Z-axis handwheel to initially move the cathode to a position at a predetermined distance from the anode surface; S4: Turn on the external magnetic drive pump, adjust the opening of the independent valves on the inlet pipes in the left, right and down directions, and observe the liquid flow state on the cathode surface to optimize the flow field uniformity. S5: Turn on the power, apply a low current density for trial plating, and at the same time, finely adjust the Z-axis handwheel to change the electrode spacing, and coordinate the adjustment of the speed of the external magnetic drive pump to observe the bubble precipitation on the cathode surface in order to achieve the coupling optimization of electric field and flow field. S6: Increase the current density to the target process value for formal electroplating; In S4, by adjusting the opening combinations of independent valves on the inlet pipes in the left, right, and lower directions on the cathode side of the transparent polypropylene electroplating tank, the direction and velocity distribution of the electroplating solution flowing from the anode area through the external filtration unit to the cathode area are controlled, thereby forming a stable and uniform fluid dynamic environment on the cathode surface.

[0014] After applying a low current density in S5, the distribution of bubbles on the surface of the cathode workpiece is observed through the transparent wall of the transparent polypropylene electroplating tank.

[0015] Compared with the prior art, the technical effects and advantages of the present invention are as follows: This electroplating apparatus for preparing a replica of an ultracold neutron conduit with an electroplated copper support layer provides a uniform and stable deposition environment. Through innovative apparatus design, it achieves precise control of the electric field distribution and fluid flow field during the electroplating process, ensuring the formation of a uniform and stable current density and solution mass transfer conditions on a large-area cathode surface. This fundamentally improves the uniformity of the coating thickness and the uniformity of the internal stress distribution, laying the foundation for subsequent successful peeling and coiling operations.

[0016] Establish an efficient online cleanliness maintenance mechanism: This mechanism aims to achieve rapid replacement of filter units without shutting down the system through a unique online filter interface design, thereby maximizing the isolation of anode mud and suspended impurities and maintaining the high cleanliness of the electroplating solution to obtain a dense, defect-free, high-quality copper plating layer.

[0017] Ensuring the ultimate uniformity and stability of the deposition environment: This is achieved through a collaborative innovative design of "large-area anode," "three-dimensional precision spacing adjustment," and "multi-path controllable flow field" to precisely control the electric field distribution and fluid flow field. This adapts to different process formulations or size requirements, improving equipment adaptability and process repeatability. It ensures the formation of a uniform and stable current density and solution mass transfer conditions on the cathode surface, thereby fundamentally guaranteeing the uniformity of coating thickness and internal stress distribution.

[0018] By placing a large-area rectangular anode plate on one side of the main body of the transparent polypropylene electroplating tank, and making its size larger than the glass substrate to be plated, while combining it with a three-dimensional adjustment mechanism to precisely position the cathode workpiece, the distribution range of the anode current field is significantly expanded, and the electric field lines are more uniformly distributed on the cathode surface. This effectively suppresses the "edge effect" caused by the mismatch between the anode and cathode areas and positional deviations in traditional electroplating. Through geometric optimization and a precise adjustment mechanism, this design achieves a high degree of symmetry and uniformity in the electric field distribution. Compared with the current density edge concentration phenomenon caused by fixed, small-area anode plates in existing technologies, it fundamentally improves the kinetic conditions of coating deposition and significantly enhances the uniformity of coating thickness and the consistency of internal stress distribution.

[0019] By setting vertical guide slots on the opposite side walls of the transparent polypropylene electroplating tank and using an external filter unit that can be vertically inserted, a physical barrier is formed between the anode and cathode. Combined with a closed-loop filtration system consisting of an external magnetic drive pump and an external cartridge filter, the electroplating solution must undergo double filtration (external filter + external filter unit) before returning to the deposition zone, achieving efficient blocking of anode mud and suspended particles. This design maintains high cleanliness of the deposition zone through the synergistic effect of the "plug-in" dynamic sealing structure and forced circulation filtration. Compared with the extensive management methods in the prior art that lack effective filtration or only use bottom circulation, which allows impurities to easily migrate to the cathode, this design significantly reduces the probability of the formation of defects such as pores and inclusions in the coating, resulting in a dense, smooth, high-quality copper film. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the electroplating apparatus of the present invention; Figure 2 This is a side view of the overall structure of the electroplating apparatus of the present invention; Figure 3 This is a top view of the overall structure of the electroplating apparatus of the present invention; Figure 4 This is a schematic diagram of the fluid circulation path in the electroplating tank of the present invention (solid arrows indicate the direction of water flow, and dashed lines indicate the direction of ion flow). Figure 5 This is a flowchart illustrating the chemical electroplating process of the present invention.

[0022] Explanation of reference numerals in the attached drawings: 1. Main body of transparent polypropylene electroplating tank; 2. Aluminum alloy support platform; 3. Conductive round tube support; 4. External filter unit; 5. Guide slot; 6. Acid-resistant water pipe; 7. External magnetic drive pump; 8. External cartridge filter; 9. Inlet pipe; 10. Support rod; 11. Three-dimensional adjustment mechanism. Detailed Implementation

[0023] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0024] Unless otherwise defined, the directions mentioned herein, such as up, down, left, right, front, back, inside, and outside, are based on the directions shown in the figures of this invention, and are explained here together.

[0025] This embodiment provides, for example Figures 1 to 5 The electroplating apparatus shown is for preparing a copper support layer for a replica ultracold neutron conduit, comprising: an electroplating tank module, an anode and cathode and a distance adjustment module, a filter module interface, a circulation module, and a cathode fixture module interface.

[0026] Electroplating tank module: The tank body is made of transparent, rigid, insulating, and corrosion-resistant material. The transparent design allows for real-time observation of the electroplating process; high rigidity ensures no deformation when bearing solutions and components; insulation properties prevent current leakage that could lead to electrolytic corrosion of the tank body or affect the electric field distribution; corrosion resistance is a fundamental requirement to ensure long-term stable operation of the equipment in acidic or alkaline electroplating solutions. A pair of parallel guide slots are precision-machined on the two opposite side walls of the tank body for installing external filter units.

[0027] Anode and cathode and spacing adjustment module: including (1) a large-area rectangular anode plate: This design aims to expand the distribution range of the current field, effectively suppress the "edge effect", and ensure that the current lines are evenly distributed on the entire surface of the glass substrate, which is the basis for obtaining a uniform coating and uniform internal stress; (2) a precision spacing adjustment mechanism: This spacing adjustment mechanism can not only realize the precise distance adjustment of the cathode relative to the anode plate in the front-back direction (Z direction), but also has the functions of up-down (Y direction) and left-right (X direction). This multi-degree-of-freedom adjustment design realizes the precise centering of the cathode clamp and the adjustment of the electrode spacing. This function ensures that the anode and cathode plates are strictly parallel and aligned, which is a prerequisite for obtaining a highly symmetrical and uniform electric field distribution. This function allows the operator to geometrically optimize the deposition environment to find the best parameters for different process formulations.

[0028] Cathode clamp module interface: The system includes a standardized interface for connecting an external cathode clamp. This interface provides: (1) a mechanical mounting point for fixing the support rod of the external clamp; (2) a positioning reference to ensure that the workpiece on the external clamp can be precisely aligned with the anode through the adjustment mechanism after installation; and (3) functional requirements: the connected external clamp should ensure that the current is uniformly introduced from the four edges of the glass substrate to be plated, and that all conductive metal parts do not come into contact with the electroplating solution.

[0029] Filter module interface: (1) Slot interface: The tank guide slot is used to install an independent external filter unit. This interface allows the filter unit to be quickly inserted and removed, and forms a reliable dynamic seal with the tank after insertion to prevent leakage. (2) Functional definition: The external filter unit must be able to effectively block the migration of anode mud and particulate impurities to the cathode area and maintain the high cleanliness of the deposition area.

[0030] The circulation system comprises an external, adjustable-speed circulation pump and connecting piping. The adjustable pump speed adds a crucial 'flow rate' control parameter for process optimization, allowing for precise matching of optimal liquid flow conditions based on factors such as cathode current density. Its water path design is highly distinctive: the outlet is located near the anode for drawing electrolyte; the inlet is located on the cathode side, with multiple inlets evenly distributed in the left, right, and bottom directions opposite the cathode workpiece. Each inlet is equipped with an independent valve for opening and closing. This design achieves directional flow (from the anode area through the filter to the cathode area) and multi-path uniform flow distribution, creating a uniform and stable hydrodynamic environment on the cathode surface, ensuring the uniformity of the mass transfer process, and working in conjunction with the filtration system to maintain high cleanliness in the deposition zone.

[0031] A precision electroplating operation method based on the above-mentioned device, characterized by comprising the following steps: S1. System Assembly and Workpiece Clamping: Vertically insert the external filter unit along the guide slot of the tank until it is sealed in place. Install the external cathode clamp with the workpiece clamped onto the support rod of the adjusting mechanism and connect the power cord.

[0032] S2. Precise Positioning and Alignment: By adjusting the Y and X directions (translation support rods) of the distance adjustment mechanism, the center of the cathode workpiece is precisely aligned with the center of the anode plate. Adjust the Z-direction handwheel to initially set the anode-cathode distance to the predetermined value (e.g., 100mm).

[0033] S3. Flow field optimization: Turn on the circulation pump and adjust the opening combination of the water inlet valves in the left, right and down directions respectively. Observe the liquid flow state on the cathode surface to form a uniform and stable flow field.

[0034] S4. Electric Field Optimization and Trial Plating: Apply a low current density (e.g., 0.5 ASD) for trial plating. Fine-tune the Z-axis electrode spacing and, in conjunction with fine-tuning the pump speed, observe the uniformity of bubble deposition on the cathode surface until the electric field and flow field reach the optimal coupling state.

[0035] S5. Formal Electroplating and Online Maintenance: Increase the current density to the target process value (e.g., 1.5 ASD) for formal electroplating. If filter elements need to be replaced, the old filter unit can be directly removed and the new unit inserted without shutting down the system.

[0036] The following description, in conjunction with the accompanying drawings, uses the electroplating of a 150μm thick oxygen-free copper layer on a 550mm × 200mm × 3mm flat glass substrate pre-plated with a Ni / Ti super mirror and a Cu seed layer as an example to illustrate the implementation of the present invention. This embodiment will detail how to achieve precision electroplating using the innovative design of this device: In this embodiment, the anode is installed as follows: Figure 1As shown, the transparent polypropylene electroplating tank body 1 is fixedly placed on the aluminum alloy support platform 2. A soluble phosphorus copper anode plate with dimensions of 650mm × 350mm × 5mm is vertically installed and fixed on the conductive round tube support 3 on one side of the tank body, and reliably connected to the positive output terminal of the DC power supply via a wire.

[0037] In this embodiment, the filter unit is installed as follows: an external filter unit 4 is vertically inserted into the guide slot 5 along the side wall of the tank until it is in place and a seal is formed. This ensures that the filter unit is securely positioned between the anode and cathode, forming an effective physical barrier.

[0038] In this embodiment, the circulation system is connected as follows: The outlet of the tank is connected to the inlet of the external magnetically driven pump 7 via an acid-resistant water pipe 6; the pump outlet is connected to the inlet of the external cartridge filter 8; finally, the outlet of the cartridge filter is connected to the inlet pipes 9 on the left, right, and bottom sides of the tank's cathode side via branch water pipes. This "tank anode area - pump - filter - tank cathode area" loop design ensures that all plating solutions undergo forced filtration before returning to the deposition area, which is crucial for maintaining high cleanliness. Check that all pipe connections are sealed.

[0039] In this embodiment, the precision clamping of the cathode fixture is as follows: the glass substrate pre-coated with Ni / Ti super mirror and Cu seed layer is placed into the external cathode fixture, and then the fixture is installed on the support rod 10 and connected to the power cord.

[0040] In this embodiment, the loading and positioning of the cathode is as follows: the fixture with the workpiece is mounted onto the three-dimensional distance adjustment mechanism 11 via the support rod 10. This mechanism integrates two mutually orthogonal precision lead screw slides, controlled by Y and Z handwheels respectively. Distance adjustment in the X direction is achieved by directly translating the support rod 10 left and right. First, by adjusting the Y-axis handwheel and translating the support rod, the edge markings of the anode plate are observed, and the center of the cathode fixture is precisely aligned with the center of the anode plate. Then, the Z-axis handwheel is rotated to initially move the cathode to a position approximately 100mm from the anode surface. This "alignment first, then distance adjustment" operation is the primary prerequisite for ensuring a symmetrical and uniform electric field distribution.

[0041] In this embodiment, the plating solution injection and system start-up and shutdown are as follows: A pre-prepared and filtered copper sulfate electroplating solution is injected into the tank, ensuring the liquid level completely submerges the anode and is at least 50 mm above the upper edge of the cathode workpiece. The circulation pump 7 is started, with its initial speed (pumping speed) set to 10 L / min. Then, the opening of each inlet valve is adjusted, and the flow field on the cathode surface is observed and optimized until it becomes uniform and stable.

[0042] In this embodiment, the electric field and flow field are optimized in synergy: After the anode and cathode are powered on, a low current density (e.g., 0.5 ASD) is first applied for a "trial plating". At this time, the surface of the cathode workpiece is observed through the transparent tank wall: a) If the bubble precipitation at the edge is significantly more severe than at the center, the Z-axis handwheel is slowly adjusted to increase the electrode spacing to weaken the edge effect; b) At the same time, the speed of the circulating pump is finely adjusted to observe the uniformity of the fluid disturbance on the cathode surface. By repeatedly finely adjusting the two key parameters of electrode spacing and liquid flow velocity until the bubble precipitation on the entire cathode surface is observed to be small and uniform, it is considered that the electric field and flow field have reached the optimal coupling state. This feedback adjustment capability based on real-time observation is the core process advantage of this invention compared to traditional fixed equipment.

[0043] In this embodiment, the formal electroplating and monitoring are as follows: the current density is steadily increased to the target process value of 1.5 ASD to begin the formal electroplating process. Throughout the entire process (lasting for several hours), the deposition status can be continuously monitored through the transparent tank, and the circulating filtration system continues to operate.

[0044] In this embodiment, post-processing involves sequentially shutting off the power and circulation pump after a predetermined time has elapsed. The workpiece is then removed, thoroughly cleaned, and subjected to a peeling process.

[0045] The copper film obtained through the above process is smooth and bright on a macroscopic scale, with uniform thickness and internal stress distribution. After being completely peeled off from the glass substrate, it is free from any warping and can be directly used for subsequent roll welding to manufacture a high-performance ultracold neutron extraction conduit.

[0046] It should be noted that, in this document, relational terms such as "one" and "two" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An electroplating apparatus for preparing a copper support layer for a replica ultracold neutron conduit, comprising a transparent polypropylene electroplating tank body (1), a three-dimensional adjustment mechanism (11), a large-area rectangular anode plate, an external filter unit (4), an external magnetic drive pump (7), an external cylindrical filter (8), and a multi-channel controllable water inlet system, characterized in that: The transparent polypropylene electroplating tank body (1) is a rigid, insulating, and corrosion-resistant transparent container. A pair of parallel guide slots (5) extending vertically are provided on its two opposite side walls. The external filter unit (4) is installed inside the transparent polypropylene electroplating tank body (1) by vertical insertion along the guide slots (5), forming a dynamic seal with the tank body after insertion. Its position is fixed between the anode and cathode. The large-area rectangular anode plate is located on one side of the transparent polypropylene electroplating tank body (1), fixed and connected to the positive terminal of a DC power supply via a conductive round tube bracket (3). Its size is larger than the glass substrate to be plated. The three-dimensional adjustment mechanism (1) 1) Located above the main body (1) of transparent polypropylene electroplating tank, including support rod (10) and two integrated precision screw slides that are orthogonal to each other. The inlet of the external magnetic drive pump (7) is connected to the outlet of the main body (1) of transparent polypropylene electroplating tank through acid-resistant water pipe (6), and the outlet is connected to the inlet of external cylindrical filter (8). The outlet of external cylindrical filter (8) is connected to the inlet pipes (9) of the anode side of transparent polypropylene electroplating tank (1) in the left, right and lower directions through branch pipes. Each inlet pipe (9) is equipped with an independent control valve to form a circulation system for realizing directional flow and multi-path uniform flow distribution.

2. The electroplating apparatus for preparing a replica ultracold neutron conduit with an electroplated copper support layer according to claim 1, characterized in that: The transparent polypropylene electroplating tank body (1) is made of transparent polypropylene material and has optical visibility to observe the internal electroplating process. The guide slot (5) is a rectangular groove opened on the opposite side walls of the transparent polypropylene electroplating tank body (1) and extends vertically to guide the insertion path of the external filter unit (4) and provide lateral restraint.

3. The electroplating apparatus for preparing a copper support layer for a replica ultracold neutron conduit according to claim 1, characterized in that: The external filter unit (4) is a detachable independent module whose shape matches the guide slot (5) and is used to block the migration of anode mud and suspended particles generated by anode dissolution to the cathode area.

4. The electroplating apparatus for preparing a copper support layer for a replica ultracold neutron conduit according to claim 1, characterized in that: The three-dimensional adjustment mechanism (11) is fixedly installed above the transparent polypropylene electroplating tank body (1). Two mutually orthogonal precision lead screw slides are integrated on both sides, and the support rod (10) is placed in the middle for connecting the external cathode clamp.

5. The electroplating apparatus for preparing a copper support layer for a replicated ultracold neutron conduit according to claim 1, characterized in that, It also includes a standardized cathode clamp interface, which is the support rod (10) of the three-dimensional adjustment mechanism (11). The external cathode clamp is placed on the support rod (10) by a hook. The external cathode clamp is used to clamp a flat glass substrate pre-coated with Ni / Ti super mirror and Cu seed layer.

6. The electroplating apparatus for preparing a copper support layer for a replica ultracold neutron conduit according to claim 1, characterized in that: The multi-channel controllable water inlet system includes three inlet pipes (9) located on the cathode side of the transparent polypropylene electroplating tank body (1), respectively on the left, right and lower sides. Each inlet pipe (9) is connected to a branch pipe from the outlet of the external cylindrical filter (8) and is equipped with an independent manual or electric valve.

7. The electroplating apparatus for preparing a copper support layer for a replica ultracold neutron conduit according to claim 6, characterized in that: The circulation system consists of an external magnetic drive pump (7), an acid-resistant water pipe (6), an external cylindrical filter (8), and branch pipes. The inlet of the external magnetic drive pump (7) is connected to the outlet of the transparent polypropylene electroplating tank body (1) through the acid-resistant water pipe (6), and the outlet is connected to the inlet of the external cylindrical filter (8).

8. A chemical electroplating operation method based on the electroplating apparatus for preparing a replica ultracold neutron conduit with an electroplated copper support layer according to any one of claims 1-7, characterized in that, Includes the following steps: S1: Insert the external filter unit (4) vertically into the guide slot (5) on the side wall of the transparent polypropylene electroplating tank body (1) until it is sealed in place, so that it is located between the large rectangular anode plate and the cathode area. S2: Install the external cathode clamp holding the glass substrate to be coated onto the support rod (10) of the three-dimensional adjustment mechanism (11), and connect the power cord to the electrical connection point; S3: By adjusting the Y-axis handwheel and translation support rod (10) of the three-dimensional adjustment mechanism (11), the center of the cathode workpiece is aligned with the center of the large-area rectangular anode plate; Rotate the Z-axis handwheel to initially move the cathode to a predetermined distance from the anode surface; S4: Turn on the external magnetic drive pump (7), adjust the opening of the independent valves on the inlet pipes (9) in the left, right and down directions, and observe the liquid flow state on the cathode surface to optimize the flow field uniformity; S5: Turn on the power, apply a low current density for trial plating, and at the same time, finely adjust the Z-axis handwheel to change the electrode spacing, and coordinate the adjustment of the speed of the external magnetic drive pump (7) to observe the bubble precipitation on the cathode surface in order to achieve the coupling optimization of electric field and flow field. S6: Increase the current density to the target process value for formal electroplating.

9. The chemical electroplating operation method of the electroplating apparatus for preparing a replica ultracold neutron conduit copper support layer according to claim 1, characterized in that: In S4, the opening degree combination of the independent valves set on the inlet pipes (9) in the left, right and lower directions on the cathode side of the transparent polypropylene electroplating tank body (1) is adjusted respectively to control the direction and speed distribution of the electroplating liquid flowing from the anode area to the cathode area through the external filter unit (4), so as to form a stable and uniform fluid dynamic environment on the cathode surface.

10. The chemical electroplating operation method of the electroplating apparatus for preparing a replica ultracold neutron conduit copper support layer according to claim 1, characterized in that: After applying a low current density in S5, the distribution of bubbles on the surface of the cathode workpiece is observed through the transparent wall of the transparent polypropylene electroplating tank body (1).

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