Large area flat coating apparatus and coating method thereof

Abstract

The application discloses a large-area plane coating device, which comprises a rack, a marble platform is placed on a shield base plate (15) in the rack, a load-bearing frame is installed on the marble platform, three slide rails (57) are arranged on an aluminum alloy base plate on the load-bearing frame in the longitudinal direction, a pre-coating platform and a coating platform are sequentially installed on the three slide rails, a gantry frame is supported on the load-bearing frame through an air floating unit, the gantry frame is provided with a driving unit, a thickness measuring unit, a slit die and an air knife unit are installed in the gantry frame, a constant-flow injection pump glue supply unit and a double-servo control unit are further installed on the gantry frame. The application further discloses a large-area plane coating method. The application belongs to the technical field of precise plane coating devices, and solves the problems of large feeding pulsation, easy material breakage, many film layer defects and low yield rate of existing large-area coating devices, and is suitable for high-end thin film large-scale precise preparation.

Description

Technical Field

[0001] This invention belongs to the technical field of precision planar coating equipment, and relates to large-area planar coating equipment. This invention also relates to a large-area planar coating method. Background Technology

[0002] Large-area planar coating is a core process for fabricating high-end thin-film devices such as perovskite photovoltaic films, optical functional coatings, new energy electrode films, and flexible electronic functional films. Compared with processes such as spraying and spin coating, planar slot coating has advantages such as controllable film thickness, high precision, large coating area, and good film uniformity, and is widely used in precision thin-film fabrication scenarios for large-size substrates. With the rapid development of downstream photovoltaic, high-end display, and new energy industries, the substrate coating size continues to increase. The industry's requirements for the thickness consistency, defect-free nature, film density, and overall uniformity of coated films have increased significantly. At the same time, stringent requirements have been placed on the stability, continuity, and pressure constancy of the feeding process.

[0003] The feeding system is a core component of planar coating equipment. The stability of the feed flow, the smoothness of the pressure, and the continuity of the feed directly determine the yield of finished products in large-area coating. Currently, traditional large-area coating equipment mostly uses single plunger pumps, screw pumps, peristaltic pumps, or single injector pumps for slurry delivery. These methods have many shortcomings in actual large-area production, failing to achieve uninterrupted, low-pulsation constant-pressure cross-flow feeding. Especially in ultra-large-size planar coating scenarios, with long coating strokes, large liquid delivery volumes, and extremely low film thickness tolerance, instability in the feeding system can lead to the scrapping of entire sheets, severely restricting the large-scale and high-quality production of large-size film products. Furthermore, existing large-area coating equipment generally lacks a dedicated pre-coating processing platform and has not been adapted to the continuous constant-pressure feeding system. In traditional processes, the slurry is directly fed into the coating die without pretreatment such as pressure stabilization, venting, and homogenization. This, coupled with pulsation defects in the feeding system, further exacerbates problems such as film thickness deviation in the initial coating area, uneven edge coating, and residual bubbles and pinholes. This results in a high rate of substrate scrap during the commissioning phase, low process tolerance, and difficulty in meeting the production demands for large areas, high precision, and high yields. In summary, current large-area planar coating equipment generally suffers from technical shortcomings such as large feeding pulsation, inability to provide uninterrupted feeding, poor film uniformity, high defect rates, and insufficient mass production stability, failing to meet the production requirements of high-end, large-size precision thin films.

[0004] Therefore, there is an urgent need to develop large-area planar coating equipment and coating methods equipped with a dual-injector constant-flow uninterrupted feeding structure and matching pre-coating process, so as to achieve uninterrupted constant pressure feeding throughout the process and significantly improve the coating accuracy and yield of large-area substrates. Summary of the Invention

[0005] The purpose of this invention is to provide a large-area planar coating equipment, which solves the problems of large material feeding pulsation, material interruption during switching, inability to continuously feed material across the cross flow, poor uniformity of film thickness in large-area coating, many coating defects, and low yield in existing large-area planar coating equipment.

[0006] Another objective of this invention is to provide a large-area planar coating method that solves the problems of material supply interruption and pulsation, coating thickness deviation, air bubbles, pinholes, horizontal defects, and uneven film thickness caused by substrate warping in the prior art.

[0007] The technical solution adopted in this invention is a large-area planar coating equipment, including a frame, a marble platform placed on a protective base plate 15 in the frame, a load-bearing frame installed on the marble platform, and three slide rails (57) arranged longitudinally on an aluminum alloy base plate on the load-bearing frame. A pre-coating platform and a coating platform are installed sequentially on the three slide rails. A gantry frame is supported on the load-bearing frame by an air-float unit. The gantry frame is equipped with a drive unit and a thickness measuring unit, a slit die head and an air knife unit are installed in the gantry frame. A constant flow injection pump glue supply unit and a dual servo control unit are also installed on the gantry frame.

[0008] Another technical solution adopted in this invention is a large-area planar coating method, which is implemented using the large-area planar coating equipment described above, according to the following steps: S1: Leveling of marble platform, pre-coating platform, and coating platform; S2: Equipment calibration and parameter preset; S3: Pre-coating condition calibration; S4: Continuous constant flow adhesive application for formal coating; S5: Finalization and recycle mass production After coating a single substrate, the glue supply controller stops the glue supply of the two injection units and the slit die head is reset; repeat the above steps to achieve continuous and stable coating of large batches of large-area substrates multiple times.

[0009] The beneficial effects of this invention are: high material feeding accuracy, enabling uninterrupted low-pulsation adhesive supply, effectively avoiding defects such as pinholes, agglomerated particles, and horizontal lines on the film surface. The bottom marble, combined with vacuum adsorption flattening, provides a high-precision reference for large-area coating; combined with an air flotation unit and dual servo closed-loop control, it achieves stable, vibration-free operation of the slit die head and precise micron-level gap adjustment, solving problems such as die head offset, uneven gap, and film thickness deviation during coating of large-size substrates. The pre-coating process completes die head wetting, pipeline pressure stabilization, venting, and process parameter calibration before formal coating, eliminating defects such as coating interruption at the starting point, film thickness offset, and uneven edges, significantly improving yield and reducing substrate debugging and scrap costs. This invention's equipment is suitable for both rigid large-size substrates such as glass and metal sheets, as well as flexible thin-film substrates, and can be used for the preparation of perovskite photovoltaic thin films, optical functional coatings, and new energy electrode thin films. Attached Figure Description

[0010] Figure 1 This is a simplified front view of the overall structure of the large-area planar coating equipment of the present invention; Figure 2 This is a simplified left view of the overall structure of the large-area planar coating equipment of the present invention; Figure 3 This is a schematic diagram of the protective cover and load-bearing frame of the large-area planar coating equipment of the present invention. Figure 4 This is a three-dimensional schematic diagram of the gantry frame structure of the large-area planar coating equipment of the present invention; Figure 5 This is a partial enlarged side view of the gantry and moving module in this invention: Figure 6 Here is a three-dimensional enlarged view of the gantry and moving module in this invention: Figure 7 This is a schematic diagram of the air knife unit structure of the large-area planar coating equipment of the present invention; Figure 8 This is a schematic diagram of the adhesive supply device of the large-area planar coating equipment of the present invention; Figure 9 This is a schematic diagram of the thickness measuring unit structure of the large-area planar coating equipment of the present invention; Figure 10 This is a three-dimensional schematic diagram of the coating platform structure of the large-area planar coating equipment of the present invention; Figure 11 This is a simplified front view of the coating platform structure of the large-area planar coating equipment of the present invention; Figure 12 This is a schematic diagram of the platform base plate structure of the large-area planar coating equipment of the present invention.

[0011] In the diagram, 1. Frame, 2. Marble platform, 3. Drive unit, 4. Slit die head, 5. Thickness measuring unit, 6. Gantry frame, 7. Glue supply unit, 8. Dual servo control unit, 9. Air flotation unit, 10. Human-machine interface, 11. Air knife unit, 12. Pre-coating platform, 13. Coating platform, 14. Protective cover base, 15. Protective cover substrate, 16. Protective cover, 17. Fresh air filter unit, 18. Fixed connecting frame, 19. Rubber pad, 20. Crossbeam one. 21. Cylinder base; 22. Cylinder; 23. Grating ruler and reading head; 24. Support; 25. Gantry base; 26. Pin and support block; 27. Horizontal support plate; 28. Vertical plate one; 29. ​​Lower support; 30. Cleanroom cable chain; 31. Air knife; 32. Rotating block; 33. Angle plate; 34. Screw; 35. Connecting frame; 36. Rotating wheel; 37. Limit nut; 38. Top plate; 39. Injection pump base; 40. Solvent bottle base; 41. Solvent bottle. 42. Solvent bottle support; 43. Adjusting handwheel; 44. First injection unit; 45. Second injection unit; 46. Sensor support; 47. Sensor head connecting block; 48. Contact sensor; 49. Threaded leveling assembly; 50. Optical axis; 51. Air flotation mounting block; 52. Optical axis mounting support; 53. Limit block; 54. Hydraulic damper; 55. Proximity switch support; 56. Liquid receiving tank; 57. Slide rail; 58. Linear motor stator; 59. Straight... 60. Linear motor mover; 61. Reading head; 62. Reading head connector; 63. Vertical plate II; 64. Grating ruler; 65. Mounting base; 66. Adjusting screw; 67. Spring; 68. Heating plate; 69. Spring hook; 70. Electric heating wire; 71. Pre-coated platform support plate; 72. Load-bearing frame; 73. Crossbeam II; 74. Solvent bottle holder; 75. Aluminum alloy base plate; 76. Slide; 77. Moving module; 78. Marble base; 79. Support assembly. Detailed Implementation

[0012] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0013] For slot coating scenarios on large-size substrates such as perovskite photovoltaic films, optical functional coatings, new energy electrode films, and flexible electronic functional films, the core innovation of this invention lies in the use of a dual-unit alternating constant flow injection pump to achieve pre-pressure matching, seamless switching, and uninterrupted low-pulsation material supply. It is equipped with an independent pre-coating and pre-treatment station, a high-rigidity marble reference platform, an air-float frictionless gantry motion mechanism, and a progressive zoned vacuum adsorption flattening structure. Furthermore, through dual servo arrangement, it achieves multi-dimensional closed-loop collaborative control of material supply flow rate, coating movement speed, and die head gap. This invention addresses industry pain points such as material supply interruption and pulsation, initial coating thickness deviation, air bubbles, pinholes, horizontal defects, and uneven film thickness caused by substrate warping in existing large-area planar coating processes from multiple dimensions, including slurry supply, process pre-treatment, mechanical reference, and motion control.

[0014] The large-area planar coating equipment of the present invention mainly includes a frame 1 (including a protective cover base 14, a protective cover substrate 15, and a protective cover 16), a marble platform 2, a gantry frame 6, a pre-coating platform 12, a coating platform 13, a slit die head 4, a drive unit 3, an air flotation unit 9, a constant flow injection pump glue supply unit 7, a dual servo control unit 8, a human-machine interface 10, and supporting thickness measurement unit 5 and air knife unit 11; in addition, rubber pads 19 and threaded leveling components 49 constitute the bottom shock absorption and leveling base to eliminate the interference of external vibration on coating accuracy.

[0015] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 8 , Figure 10 The specific structure of the large-area planar coating equipment of the present invention includes a frame 1, the bottom of which is called a protective cover base 14. Four corners of the lower end face of the protective cover base 14 are respectively provided with casters, and adjusting feet are provided between each caster to realize the movement, height adjustment, and position locking of the entire equipment. A protective cover base plate 15 is fixedly installed on the upper end face profile of the protective cover base 14. A protective cover 16 is installed upwards along the perimeter of the protective cover base plate 15. A human-machine interface 10 is provided on the outer surface of the protective cover 16 at the height of the operating position. A fresh air filter unit 17 is provided on the top of the protective cover 16. A layer of rubber pad 19 is laid on the protective cover base plate 15 for shock absorption. A marble platform 2 is placed on the rubber pad 19. The marble platform 2 is connected to the protective cover base plate 15 by a fixed connecting frame 18 around its perimeter. Figure 3 ; The marble platform 2 is positioned along the longitudinal centerline on the upper surface of the protective substrate 15. The natural marble substrate has a low coefficient of thermal deformation, high overall flatness, and strong rigidity, serving as a uniform precision benchmark for the entire machine and avoiding film deviations caused by frame deformation during the coating process of large-size substrates. Multiple anti-vibration pads are arranged on both longitudinal sides of the upper surface of the marble platform 2. Each anti-vibration pad is supported upwards by a set of threaded leveling components 49, collectively supporting the load-bearing frame 71. (See...) Figure 2 ; See Figure 10 An aluminum alloy substrate 74 is fixed to the upper part of the load-bearing frame 71. The aluminum alloy substrate 74 is fixed to the load-bearing frame 71 by screws. Three slide rails 57 are arranged parallel to the longitudinal direction of the aluminum alloy substrate 74. A pre-coating platform 12 and a coating platform 13 are installed on the three slide rails 57 in sequence along the material feeding direction. A liquid receiving tank 56 is also installed on the aluminum alloy substrate 74. An air knife unit 11 is also provided above the pre-coating platform 12. A marble seat 77 in the X direction is arranged on both sides of the longitudinal side of the aluminum alloy substrate 74. Each marble seat 77 is equipped with a set of air bearings of air bearing unit 9. The two sets of air bearings are supported upward on the lower surface of the horizontal support plates 27 on both sides of the gantry frame 6. The gantry frame 6 is equipped with a drive unit 3. The drive unit 3 is a linear motor module composed of linear motor stator 58 and linear motor mover 59, which can drive the gantry frame 6 to move at a constant speed in the X direction along the length of the substrate. The gantry frame 6 is equipped with a thickness measuring unit 5 and a slit die head 4, which is located above the pre-coating platform 12 and the coating platform 13. The gantry frame 6 is also equipped with a constant flow injection pump glue supply unit 7 and a dual servo control unit 8. The constant flow injection pump glue supply unit 7 is located above the coating platform 13. The dual servo control unit 8 performs linkage control on the constant flow injection pump glue supply unit 7 and the drive unit 3 respectively, so as to realize the closed-loop coordination of glue supply flow, walking speed and die head Z-axis clearance. The pre-coating platform 12 is set at the feeding start end of the coating platform 13. The table height and die working gap of the pre-coating platform 12 are strictly consistent with those of the coating platform 13. This is a key innovative station that distinguishes this invention from traditional planar coating equipment. Before the formal substrate coating, the pre-coating platform 12 completes the pre-flow of slurry, overall pre-wetting of the lip of the slit die head 4, pipeline pressure establishment, pipeline air bubble removal, and film thickness process parameter calibration. The venting, wetting, and parameter adjustment are all completed at the pre-coating station, avoiding direct damage to expensive large-size substrates during the adjustment process.

[0016] See Figure 10 The load-bearing frame 71 has horizontal optical shafts 50 fixed longitudinally on both sides of the outer facade. The optical shafts 50 are fitted with air bearing sleeves of air bearing units 9. The air bearing sleeves are fixedly connected to the air bearing mounting blocks 51. The air bearing mounting blocks 51 are fixedly connected to the upright plate 28 of the gantry frame 6. The air bearing unit 9 is composed of air bearing sleeves, air bearings and matching locking components. Three air bearing units 9 are evenly distributed on both sides of the gantry frame 6. When the air bearing unit 9 is working, the air bearings suspend the gantry frame 6 as a whole on a pair of marble seats 77. Each air bearing sleeve on each side forms an air mold with its corresponding optical shaft 50. Then, the drive unit 3 is used to realize the gantry frame 6 moving in the X direction without contact or friction under the guidance of the optical shaft 50, completely eliminating the mechanical friction and vibration of traditional ball bearings and linear guides, and ensuring that the coating speed of the long stroke slit die head 4 is uniform and stable. Z-axis adjustment mechanisms are provided at both ends of the horizontal direction of the gantry frame 6. The Z-axis adjustment mechanism is equipped with a grating ruler 63 for full closed-loop position feedback. The Z-axis adjustment mechanism is used to drive the slit die head 4 to move up and down, and adjust the gap between the slit die head 4 and the pre-coating platform 12 and the coating platform 13, so as to realize the Z-axis micron-level gap adjustment at both ends of the slit die head 4 and ensure that the lip of the die head is horizontal. The human-machine interface 10 is connected to the drive unit 3, slit mold head 4, thickness measurement unit 5, constant flow injection pump glue supply unit 7, and dual servo control unit 8. The human-machine interface 10 is used to input various process parameters, display the equipment operating status in real time, provide fault alarms, and set differentiated parameters for multiple execution units, so as to realize the automated control of the whole machine.

[0017] Reference Figure 4 The specific structure of the Z-axis adjustment mechanism at both ends of the gantry frame 6 is as follows: the top transverse main beam of the gantry frame 6 includes two horizontal beams 20 and 72 spaced side by side (which together serve as transverse supports). Each end of the horizontal beams 20 and 72 is fixedly connected to a lower support 29. The two lower supports 29 at each end are connected to a horizontal support plate 27. Each horizontal support plate 27 is fixedly connected to a vertical plate 28 along its outer edge. The inner surface of each vertical plate 28 is fixedly connected to the air flotation mounting block 51. A dust-free drag chain 30 is provided on the outer surface of the vertical plate 28 on one side. One end of the dust-free drag chain 30 is connected to the electrical equipment on the horizontal support plate 27, and the other end is connected to the protective cover base plate 15 for storing cables and air pipes that move in the Z-axis direction. Reference Figure 5 , Figure 6 The constant flow injection pump glue supply unit 7 is specifically fixed on the crossbeam 1 20; the air knife unit 11 is specifically fixed inside the crossbeam 2 72; a gantry seat 25 is provided between the crossbeam 1 20 and the crossbeam 2 72, the gantry seat 25 serves as the Z-axis sliding base, and the slit mold head 4 is installed under the gantry seat 25. The two ends of the gantry 25 are hinged to the two sides of the slide 75 via bearings on both sides. The back of the slide 75 is connected to the slider of the moving module 76 (the moving module 76 can drive the slide 75 to move the gantry 25 up and down for fine adjustment, so as to independently adjust the Z-axis gap at both ends of the slit die head 4 and compensate for the deformation of the large span gantry 25). The top of the slide 75 is fixed with a cylinder seat 21, and the cylinder seat 21 is hinged downward to a cylinder 22. The piston rod end of the cylinder 22 is fixed downward to the horizontal support plate 27 with screws. The slide 75 is used to output the feedback of the cylinder 22, which drives the gantry 25 to move up and down (the moving distance is significantly larger than that of the moving module 76), so as to adjust the coating gap by moving the slit die head 4 up and down in the Z direction. It also includes a grating ruler and a reading head 23. The grating ruler is vertically arranged on the side of the moving module 76. The reading head corresponding to the grating ruler is mounted on the support 24. The support 24 is hinged to the horizontal support plate 27 by a pin and a support block 26. The cylinder 22 drives the gantry 25 to rise and fall in the vertical direction. The grating ruler and the reading head 23 collect the vertical displacement in real time, which can realize the Z-direction closed-loop feedback of the gantry 25.

[0018] The second method for setting up the Z-axis adjustment mechanism is to replace the driving method of cylinder 22 with a servo motor-lead screw-slide bar closed-loop drive structure. A lead screw and a pair of parallel slide bars are vertically arranged on the base. The servo motor drives the lead screw to rotate, causing the slide to make vertical feed movements. The slide is guided linearly through a sliding bearing and the slide bars. A grating ruler 63 collects the vertical position signal of the slide in real time, realizing full closed-loop position feedback. A limit contact block is configured at the lower end of the lead screw as a hardware limit protection. The slide is hinged to the end of the gantry frame 6 through a hinge shaft. This structure can achieve independent micron-level Z-axis adjustment at both ends of the gantry frame 6, compensating for the deformation of the large-span gantry frame itself, further ensuring the overall horizontal level of the slit die head 4, and reducing the gap deviation at both ends of the die head. It is especially suitable for coating ultra-large substrates. The remaining structures in this second method remain unchanged from the first method. The marble platform 2, pre-coating platform 12, dual-unit alternating constant flow injection pump glue supply unit 7, air flotation unit 9, and dual servo control unit 8 are all retained.

[0019] Reference Figure 7 The structure of the air knife unit 11 includes a top plate 38 and a connecting frame 35. Two angle plates 33 are fixedly connected downwards at both ends of the top plate 38. A rotating block 32 is respectively provided on the inner surface of the lower end of each angle plate 33. An air knife 31 is fixedly connected between the two rotating blocks 32. The angle plates 33 can adjust the tilt angle of the air knife 31. A screw 34 is provided on the outer side of each angle plate 33. A connecting frame 35 passes through both screws 34. The two screws 34 extend upwards through the connecting frame 35 and are fixedly connected to the top plate 38. The connecting frame 35 and... The second crossbeam 72 is fixedly connected. Each screw 34 is provided with a limiting nut 37 at the upper and lower positions of the connecting frame 35. A rotating wheel 36 is also provided between each upper limiting nut 37 and the connecting frame 35. During operation, the upper and lower relative positions of the connecting frame 35 and the top plate 38 are adjusted by rotating the rotating wheel 36 to control the height between the air knife unit 11 and the pre-coating platform 12 and the coating platform 13. The lower limiting nut 37 is used to lock and fix the position. The air knife 31 is connected to a clean compressed air source, which can perform airflow pre-drying treatment on the coated wet film.

[0020] Reference Figure 8 The constant flow injection pump glue supply unit 7 is the core innovative material supply unit of this invention. It includes two injection units, namely the first injection unit 44 and the second injection unit 45. The first injection unit 44 and the second injection unit 45 are fixedly mounted on the crossbeam 20 using the injection pump base 39. It also includes an associated constant flow reversing valve group, pressure detection component and glue supply controller. The first injection unit 44 and the second injection unit 45 are arranged symmetrically in parallel. The two injection units are equipped with independent servo drive mechanisms, and both can independently complete the actions of extracting and pushing the material for injection. Each injection unit is equipped with an independent glue supply unit. Each glue supply unit includes a solvent bottle bracket 42 and a solvent bottle base 40 fixed together. The solvent bottle base 40 is connected and fixed to the crossbeam 20. A solvent bottle 41 is installed in the solvent bottle bracket 42 and the solvent bottle base 40. An adjustment handwheel 43 is provided at the opening of the solvent bottle bracket 42. The adjustment handwheel 43 is used to lock and fix the solvent bottle 41 after it is placed in the solvent bottle bracket 42 and the solvent bottle base 40.

[0021] Both sets of glue supply units can achieve precise flow control with micro-upgrades, featuring closed-loop feedback, intelligent calibration, and overload protection. They exhibit low shear force for highly sensitive perovskite slurries, effectively suppressing flow pulsation and material interruption caused by traditional screw pumps and single injection pumps. This reduces defects such as transverse lines, pinholes, and particle agglomeration on the film surface from the slurry supply source. The glue supply controller incorporates dual-unit synchronous linkage control logic. During normal coating, one injection unit performs constant-flow pushing to supply glue, while the other injection unit simultaneously completes material extraction, storage, and pre-pressure stabilization. Before the injection unit in the pushing operation reaches the end of its stroke, the glue supply controller drives the standby injection unit to perform pressure following and flow pre-synchronization. Once the pressure detection component indicates that the pressure and flow values ​​of the two injection units are completely matched, the constant-flow reversing valve group is controlled to seamlessly switch the supply path. The first pushing unit switches to the material extraction and storage state, and the standby pushing unit takes over the external glue supply, repeating the cycle to achieve uninterrupted, low-pulsation, constant-pressure, and constant-flow slurry supply throughout the entire process.

[0022] Reference Figure 9 The thickness measurement unit 5 consists of a sensor bracket 46, with a sensor head connecting block 47 at each end. Each sensor head connecting block 47 houses a contact sensor 48. The sensor bracket 46 is fixedly mounted on the gantry frame 6 (the thickness measurement unit 5 and the air knife unit 11 are respectively arranged on the front and rear sides of the slit die head 4 in the X direction) and can move synchronously with the slit die head 4. In the S3 pre-coating calibration step, after the pre-coating platform 12 completes the pre-coating, the contact sensor 48 detects the thickness of the pre-coated film and feeds the thickness data back to the dual servo control unit 8. The dual servo control unit 8 automatically corrects the adhesive flow rate and the Z-axis gap parameters of the die head based on the deviation between the measured film thickness and the target film thickness, realizing a closed-loop process of "pre-coating - film thickness detection - automatic parameter correction - formal coating". The design of the thickness measurement unit 5 reduces manual intervention and further improves the overall consistency of film thickness on large-area substrates, making it particularly suitable for the production of high-precision optical coatings.

[0023] Reference Figure 10The lower end face of the load-bearing frame 71 is equipped with a total of six sets of threaded leveling components 49 (three sets on each side). The upper surface of the load-bearing frame 71 is provided with a coating platform 13, a pre-coating platform 12 and a liquid receiving tank 56 along the longitudinal center line. The coating platform 13 and the pre-coating platform 12 are set on the slide rail 57. An aluminum alloy base plate 74 is installed on the load-bearing frame 71. Marble seats 77 are installed on both sides of the aluminum alloy base plate 74. A grating ruler 63 is installed inside one marble seat 77. A second vertical plate 62 and a drive unit 3 are provided on the load-bearing frame 71 corresponding to the grating ruler 63. A reading head connecting seat 61 is fixed on the second vertical plate 62. A reading head 60 is installed on the reading head connecting seat 61. The reading head 60 can read the scale signal of the grating ruler 63 and realize the full closed-loop position feedback of the gantry frame 6 in the X direction. The drive unit 3 includes a linear motor stator 58 and a linear motor mover 59. The linear motor stator 58 is fixed on the inner surface of the marble base 77, and the linear motor mover 59 is connected to the inner side of the second vertical plate 62. The top of the second vertical plate 62 is rigidly connected to the first vertical plate 28 on the gantry frame 6, providing X-direction driving force for the gantry frame 6. The two ends of the optical axis 50 are installed in the optical axis mounting bracket 52, which is fixed to the two end faces of the load-bearing frame 71. The air-bearing mounting blocks 51 on both sides are respectively connected to the inner side of the vertical plate 28 on the gantry frame 6 to realize the frictionless movement of the Z-axis air-bearing optical axis. Limit blocks 53 are provided at both ends of the optical axis 50. The limit blocks 53 are mechanical limits for Z-axis movement to prevent the movement from exceeding the stroke and damaging the parts. Hydraulic buffers 54 and proximity switch brackets 55 are also provided at both ends of the optical axis 50. The hydraulic buffers 54 are used to prevent the vertical plate 28 from being deformed by collision. Each proximity switch bracket 55 is equipped with a proximity switch as an electrical limit and position feedback for Z-axis movement.

[0024] Reference Figure 11 , Figure 12A heating plate 67 is fixed to the lower end face of the coating platform 13. Electric heating wires 69 are densely distributed on the heating plate 67. Multiple mounting seats 64 are located below the heating plate 67, each housing an adjusting screw 65. Each adjusting screw 65 passes upwards through the heating plate 67 and the pre-coating platform support plate 70. The adjusting screw 65 is adjusted in height by counter-mounting the mounting seat 64. Screws on the lower side of the mounting seat 64 are inserted into the slide rail 57, forming a support assembly 78. The heating plate 67 and the pre-coating platform support plate 70 are mounted on three slide rails 57 using a three-point mounting method. Three support components 78 are respectively set below 70 (each three support components 78 are distributed in a triangle), which can realize the adjustment of the longitudinal position of the pre-coating platform 12 and the coating platform 13 in the X-axis direction; the spring hooks 68 are C-shaped hooks respectively installed on the bottom of the heating plate 67 and the mounting base 64, which work together to realize the floating support of the heating plate 67 and the pre-coating platform support plate 70, eliminating thread gaps. By turning the adjusting screws 65, the pre-coating platform 12 and the coating platform 13 can be leveled at multiple points, which is called the spring gap elimination component; the aluminum alloy base plate 74 is a common bearing base, supporting the slide rail 57 and the liquid receiving tank 56.

[0025] There is no heating device under the pre-coating platform 12, only the pre-coating platform support plate 70. The connection method is the same as the installation method of the coating platform 13 and the heating plate 67 (both are three-point support methods), and it is adjustable.

[0026] The pre-coating platform 12 and the coating platform 13 can be moved slightly in the X direction to adjust their positions via the slide rail 57. They do not move during the coating process; only the gantry frame 6 drives the die head to move in the X direction to complete the coating.

[0027] The coating platform 13 has multiple horizontal exhaust channels inside, and the surface is densely covered with horizontally and vertically perpendicular adsorption holes. These adsorption holes form adsorption zones that gradually expand outwards from small to large. The exhaust channels are connected to a vacuum mechanism and a gas precision regulation component. After the substrate is loaded, the adsorption zone gradually expands outwards from the initial position on the substrate, allowing the rigid substrate and flexible substrate to gradually adhere to the marble reference surface. This not only fully flattens the substrate but also avoids sinking and deformation of the flexible substrate caused by strong adsorption at a single point.

[0028] The working principle of this invention is: 1) The dual-unit alternating constant flow injection pump glue supply unit 7 is the core, realizing micro-volume high precision, uninterrupted and pulsation-free constant pressure material supply; the marble platform 2 ensures the equipment's reference rigidity and planar accuracy; the air flotation unit 9 and dual servo control unit 8 realize micron-level gap adjustment and stable displacement of the slit die head 4; the pre-coating platform 12 is added to complete the pre-treatment of the slurry before coating and the working condition calibration. From the multiple dimensions of material supply accuracy, mechanical stability, motion control and process pre-treatment, it solves problems such as horizontal lines, uneven thickness, air bubbles, pinholes and edge defects in large-area coating film layers, meets the needs of large-area, high yield and large-scale mass production of high-end sensitive slurries such as perovskite photovoltaic film, optical functional coating and new energy electrode film.

[0029] 2) The marble platform 2 is made of natural marble, which has high flatness, small thermal deformation and strong structural rigidity, providing high-precision reference support for the whole machine and avoiding film deviation caused by equipment deformation when coating large-size substrates; the coating platform 13 is set above the marble platform 2 and is used to support and position the large-size substrate to be coated; the pre-coating platform 12 is set at the feeding start end of the coating platform 13, and the table height and die head working gap are consistent with the coating platform 13. It is used to complete the pre-flow of slurry, pre-wetting of the lip of the slit die head 4, pipeline pressure stabilization, bubble discharge and film thickness parameter calibration before formal coating.

[0030] 3) The slit die head 4 is mounted above the coating platform 13 and the pre-coating platform 12 to uniformly coat the slurry onto the substrate surface; the drive unit 3 uses a linear motor to drive the gantry frame 6 to achieve uniform translation of the slit die head 4 along the length of the substrate; the air flotation unit 9 is located on the left and right sides of the gantry frame and ensures that the die head moves smoothly without friction or vibration through air flotation bearings (air flotation bushings).

[0031] 4) The constant flow injection pump dispensing unit, as the dispensing unit, adopts a dual-unit alternating constant flow injection pump structure. The two injection units are symmetrically arranged in parallel, and each unit is independently equipped with a servo drive mechanism, which has the function of alternating extraction and injection. The two sets of injection units realize the continuous delivery and distribution through the reversing valve group, and can perform four working modes: continuous transmission, quantitative metering, timed quantitative, and timed start and stop. The dispensing controller has a built-in dual-unit synchronous linkage logic. When one injection unit pushes the dispensing material with constant flow, the other unit simultaneously completes the extraction, storage and pressure stabilization. Before the end of the push unit's stroke, the pressure pre-matching and flow pre-synchronization of the two units are completed in advance. The dispensing units are seamlessly switched through the reversing valve group to achieve uninterrupted, high-precision constant flow and constant pressure dispensing. The system has closed-loop control, intelligent calibration and overload protection functions, can provide real-time feedback of operating parameters, accurately control the micro-level dispensing flow, and has low shear force.

[0032] 5) The dual servo control units respectively link and control the constant flow injection pump glue supply unit and the slit die head drive unit to achieve closed-loop coordinated control of material flow rate, coating speed and die head gap.

[0033] The large-area planar coating method of the present invention is implemented using the large-area planar coating equipment described above, according to the following steps: S1: Leveling of marble platform, pre-coating platform, and coating platform; The four corner casters at the lower end of the protective cover base 14, as well as the adjusting feet between each caster, ensure that the marble platform 2 is level and minimize the impact on the coating platform accuracy. The level of the load-bearing frame 71 and the aluminum alloy base plate 74 is adjusted by the threaded leveling component 49 to ensure the level of the three slide rails 57 on the aluminum alloy base plate 74. Then, by using two sets of three support components 78 set on the three slide rails 57, combined with each spring backlash elimination component, the adjustment thread gap is effectively eliminated. The triangular layout leveling method is adopted to ensure that the pre-coating platform 12 and the coating platform 13 on the aluminum alloy substrate 74 meet the flatness requirements required for coating.

[0034] S2: Equipment calibration and parameter preset The reference plane of the marble platform 2, the translation accuracy of the slit die head 4, and the working gap of the air flotation unit 9 are calibrated by the dual servo control unit 8. Process information such as target film thickness, coating speed, glue supply flow rate, dual unit switching threshold, and timing / quantitative parameters are entered into the human-machine interface 10. The vacuum adsorption flattening of the coating platform 13 uses vacuum adsorption to fix the substrate. The adsorption flattening structure consists of several adsorption grooves or adsorption holes on the reference plane that are basically perpendicular to the direction of travel of the coating substrate. The adsorption starts from one point of the coating substrate and gradually expands to both sides of the coating substrate, so that the coating substrate is tightly attached to the reference plane of the flattening structure. At the same time, the adsorption gas is precisely adjusted to finally achieve stable platform adsorption force, so that the substrate is firmly adsorbed and the coating substrate is flattened.

[0035] S3: Pre-coating condition calibration Drive the slit die head 4 to move above the pre-coating platform 12, turn on the constant flow injection pump to continuously supply glue, complete the overall wetting of the lip of the slit die head 4 and establish the pipeline pressure; observe the pre-coating film formation state, and fine-tune parameters such as glue supply flow rate, coating speed, and die head gap to match the formal coating conditions.

[0036] S4: Continuous constant flow adhesive application for formal coating. The substrate to be coated is precisely positioned on the coating platform 13. Initially, the first injection unit 44 supplies adhesive with constant pressure and constant flow. When the first injection unit 44 is near the end of its stroke, the adhesive supply controller drives the second injection unit 45 to follow the pressure and synchronize the flow. After the pressure and flow of the two units are completely consistent, the second injection unit 45 is seamlessly switched to supply adhesive through the reversing valve group, and the first injection unit 44 returns to extract the stored material. The two units alternate in this cycle to achieve uninterrupted constant flow adhesive supply throughout the process. The dual servo control units work together to control the slit die head 4 to move evenly, completing the continuous coating of the entire substrate surface.

[0037] S5: Finalization and recycle mass production After coating a single substrate, the glue supply controller stops the glue supply of the two injection units, and the slit die head 4 is reset; repeat the above steps to achieve continuous and stable coating of large batches of large-area substrates multiple times.

[0038] Example 1 The structure of the large-area planar coating equipment in this embodiment 1 includes a frame 1. A marble platform 2 is placed on the protective base plate 15 in the frame 1 via a rubber pad 19. A load-bearing frame 71 is installed on the upper surface of the marble platform 2. Three slide rails 57 are arranged parallel to each other along the longitudinal direction on the aluminum alloy base plate 74 on the load-bearing frame 71. A pre-coating platform 12, a coating platform 13, and a liquid receiving tank 56 are sequentially installed on the three slide rails 57 along the material feeding direction. A gantry frame 6 is supported on the load-bearing frame 71 by an air flotation unit 9. A drive unit 3 is configured in the gantry frame 6. A thickness measuring unit 5, a slit die head 4, and an air knife unit 11 are installed in the gantry frame 6. The slit die head 4 is located above the pre-coating platform 12 and the coating platform 13. The air knife unit 11 is located above the pre-coating platform 12.

[0039] The bottom of the frame 1 is called the protective cover base 14. The four corners of the lower end face of the protective cover base 14 are respectively provided with casters, and the wheels are provided with adjustment feet. The upper end face profile of the protective cover base 14 is fixedly installed with a protective cover base 15. The protective cover 16 is installed upward along the perimeter of the protective cover base 15. The outer surface of the protective cover 16 is provided with a human-machine interface 10 corresponding to the height of the operating station.

[0040] Example 2 The structure of the large-area planar coating equipment in this embodiment 2 includes a frame 1. A marble platform 2 is placed on the protective base plate 15 in the frame 1 via a rubber pad 19. A load-bearing frame 71 is installed on the upper surface of the marble platform 2. Three slide rails 57 are arranged parallel to each other along the longitudinal direction on the aluminum alloy base plate 74 on the load-bearing frame 71. A pre-coating platform 12, a coating platform 13, and a liquid receiving tank 56 are installed sequentially on the three slide rails 57 along the material feeding direction. A gantry frame 6 is supported on the load-bearing frame 71 by an air flotation unit 9. A drive unit 3 is configured in the gantry frame 6. A thickness measuring unit 5, a slit die head 4, and an air knife unit 11 are installed in the gantry frame 6. The slit die head 4 is located above the pre-coating platform 12 and the coating platform 13. The air knife unit 11 is located above the pre-coating platform 12.

[0041] The bottom of the frame 1 is called the protective cover base 14. The four corners of the lower end face of the protective cover base 14 are respectively provided with casters, and the wheels are provided with adjustment feet. The upper end face profile of the protective cover base 14 is fixedly installed with a protective cover base 15. The protective cover 16 is installed upward along the perimeter of the protective cover base 15. The outer surface of the protective cover 16 is provided with a human-machine interface 10 corresponding to the height of the operating station.

[0042] The marble platform 2 is connected to the protective cover base plate 15 by a fixed connecting frame 18 around its perimeter. Multiple anti-vibration pads are arranged on both sides of the upper surface of the marble platform 2. Each anti-vibration pad is supported by a set of threaded leveling components 49 to support the load-bearing frame 71.

[0043] An aluminum alloy base plate 74 is mounted on the load-bearing frame 71. Marble seats 77 are mounted on both sides of the aluminum alloy base plate 74. A grating ruler 63 is mounted inside one side of the marble seat 77. A second upright plate 62 and a drive unit 3 are provided on the load-bearing frame 71 corresponding to the grating ruler 63. A reading head connecting seat 61 is fixed on the second upright plate 62. A reading head 60 is mounted on the reading head connecting seat 61.

[0044] Example 3 The structure of the large-area planar coating equipment in this embodiment 3 includes a frame 1. A marble platform 2 is placed on the protective base plate 15 in the frame 1 via a rubber pad 19. A load-bearing frame 71 is installed on the upper surface of the marble platform 2. Three slide rails 57 are arranged parallel to each other along the longitudinal direction on the aluminum alloy base plate 74 on the load-bearing frame 71. A pre-coating platform 12, a coating platform 13, and a liquid receiving tank 56 are sequentially installed on the three slide rails 57 along the material feeding direction. A gantry frame 6 is supported on the load-bearing frame 71 by an air flotation unit 9. A drive unit 3 is configured in the gantry frame 6. A thickness measuring unit 5, a slit die head 4, and an air knife unit 11 are installed in the gantry frame 6. The slit die head 4 is located above the pre-coating platform 12 and the coating platform 13. The air knife unit 11 is located above the pre-coating platform 12.

[0045] The bottom of the frame 1 is called the protective cover base 14. The four corners of the lower end face of the protective cover base 14 are respectively provided with casters, and the wheels are provided with adjustment feet. The upper end face profile of the protective cover base 14 is fixedly installed with a protective cover base 15. The protective cover 16 is installed upward along the perimeter of the protective cover base 15. The outer surface of the protective cover 16 is provided with a human-machine interface 10 corresponding to the height of the operating station.

[0046] The marble platform 2 is connected to the protective cover base plate 15 by a fixed connecting frame 18 around its perimeter. Multiple anti-vibration pads are arranged on both sides of the upper surface of the marble platform 2. Each anti-vibration pad is supported by a set of threaded leveling components 49 to support the load-bearing frame 71.

[0047] An aluminum alloy base plate 74 is mounted on the load-bearing frame 71. Marble seats 77 are mounted on both sides of the aluminum alloy base plate 74. A grating ruler 63 is mounted inside one side of the marble seat 77. A second upright plate 62 and a drive unit 3 are provided on the load-bearing frame 71 corresponding to the grating ruler 63. A reading head connecting seat 61 is fixed on the second upright plate 62. A reading head 60 is mounted on the reading head connecting seat 61.

[0048] The outer facades on both sides of the load-bearing frame 71 are fixed with horizontal optical shafts 50 along the longitudinal direction. The optical shafts 50 are fitted with air bearing sleeves of air bearing units 9. The air bearing sleeves are fixedly connected to the air bearing mounting blocks 51. The air bearing mounting blocks 51 are fixedly connected to the vertical plate 28 of the gantry frame 6. The air bearing unit 9 is composed of air bearing sleeves, air bearings and matching locking components. Three air bearing units 9 are evenly distributed on both sides of the gantry frame 6.

[0049] Example 4 The structure of the large-area planar coating equipment in this embodiment 4 includes a frame 1. A marble platform 2 is placed on the protective base plate 15 in the frame 1 via a rubber pad 19. A load-bearing frame 71 is installed on the upper surface of the marble platform 2. Three slide rails 57 are arranged parallel to each other along the longitudinal direction on the aluminum alloy base plate 74 on the load-bearing frame 71. A pre-coating platform 12, a coating platform 13, and a liquid receiving tank 56 are installed sequentially on the three slide rails 57 along the material feeding direction. A gantry frame 6 is supported on the load-bearing frame 71 by an air flotation unit 9. A drive unit 3 is configured in the gantry frame 6. A thickness measuring unit 5, a slit die head 4, and an air knife unit 11 are installed in the gantry frame 6. The slit die head 4 is located above the pre-coating platform 12 and the coating platform 13. The air knife unit 11 is located above the pre-coating platform 12.

[0050] The bottom of the frame 1 is called the protective cover base 14. The four corners of the lower end face of the protective cover base 14 are respectively provided with casters, and the wheels are provided with adjustment feet. The upper end face profile of the protective cover base 14 is fixedly installed with a protective cover base 15. The protective cover 16 is installed upward along the perimeter of the protective cover base 15. The outer surface of the protective cover 16 is provided with a human-machine interface 10 corresponding to the height of the operating station.

[0051] The marble platform 2 is connected to the protective cover base plate 15 by a fixed connecting frame 18 around its perimeter. Multiple anti-vibration pads are arranged on both sides of the upper surface of the marble platform 2. Each anti-vibration pad is supported by a set of threaded leveling components 49 to support the load-bearing frame 71.

[0052] An aluminum alloy base plate 74 is mounted on the load-bearing frame 71. Marble seats 77 are mounted on both sides of the aluminum alloy base plate 74. A grating ruler 63 is mounted inside one side of the marble seat 77. A second upright plate 62 and a drive unit 3 are provided on the load-bearing frame 71 corresponding to the grating ruler 63. A reading head connecting seat 61 is fixed on the second upright plate 62. A reading head 60 is mounted on the reading head connecting seat 61.

[0053] The outer facades on both sides of the load-bearing frame 71 are fixed with horizontal optical shafts 50 along the longitudinal direction. The optical shafts 50 are fitted with air bearing sleeves of air bearing units 9. The air bearing sleeves are fixedly connected to the air bearing mounting blocks 51. The air bearing mounting blocks 51 are fixedly connected to the vertical plate 28 of the gantry frame 6. The air bearing unit 9 is composed of air bearing sleeves, air bearings and matching locking components. Three air bearing units 9 are evenly distributed on both sides of the gantry frame 6.

[0054] Z-axis adjustment mechanisms are provided at both ends of the horizontal transverse direction of the gantry frame 6. The top transverse main beam of the gantry frame 6 includes two horizontal beams 20 and 72 spaced side by side. A lower support 29 is fixedly connected to each end of the horizontal beams 20 and 72. The two lower supports 29 at each end are connected to a horizontal support plate 27. A vertical plate 28 is fixedly connected to the outer edge of each horizontal support plate 27. The inner surface of the vertical plate 28 on each side is fixedly connected to the air flotation mounting block 51. A dust-free drag chain 30 is provided on the outer surface of the vertical plate 28 on one side. The slit mold head 4 is installed under the gantry seat 25. A gantry seat 25 is provided between the first crossbeam 20 and the second crossbeam 72. The two ends of the gantry seat 25 are hinged to the sides of the slide 75 via bearings on both sides. The back of the slide 75 is connected to the slider of the moving module 76. A cylinder seat 21 is fixed to the top of the slide 75. A cylinder 22 is hinged downward to the cylinder seat 21. The piston rod end of the cylinder 22 is fixed downward to the horizontal support plate 27 by screws.

[0055] Example 5 This embodiment 5 is a large-area planar coating method based on the structure of embodiment 4. Combining the innovative structure of this invention, it fully realizes uninterrupted low-pulsation slit coating of large-size substrates, and includes the following steps: S1: Multi-level leveling of marble platform 2, pre-coating platform 12, and coating platform 13. The bottom layer of the equipment relies on rubber pads 19 and threaded leveling components 49 to complete basic vibration reduction and coarse leveling; an aluminum alloy base plate 74 is set above the load-bearing frame 71, and three sets of slide rails 57 are arranged on the aluminum alloy base plate 74. Springs 66 are used to eliminate the return gap of the threaded adjustment; the leveling method adopts a triangular layout of leveling bolts to ensure the stability of the coating plane system. The high-precision marble pre-coating platform 12 and coating platform 13 are placed on the aluminum alloy base plate 74. Relying on the high-precision flatness of the marble platform 2 itself, the coating benchmark of the whole machine is established, reducing the impact of foundation deformation on the coating flatness.

[0056] S2: Equipment Calibration and Parameter Preset. Calibration and verification are performed by calibrating the reference surface of the marble platform 2, the translation accuracy of the slit die head 4, and the working gap of the air flotation unit 9 through the dual servo control unit 8; the operator enters process information such as target film thickness, coating speed, glue supply flow rate, dual unit switching threshold, and timing / quantitative parameters on the human-machine interface 10; the vacuum adsorption equipment of the coating platform 13 is turned on, and the adsorption area is gradually expanded from the local starting position of the substrate to both sides of the substrate. The gas flow rate is precisely adjusted to make the substrate completely adhere to the marble reference surface and complete the flattening and positioning of the substrate.

[0057] S3: Pre-coating condition calibration is a unique process step of this invention. The drive unit 3 drives the gantry frame 6 to move the slit die head 4 above the pre-coating platform 12, and starts the constant flow injection pump glue supply unit 7 to continuously output slurry, fully wetting the lip of the slit die head 4, establishing a stable working pressure in the pipeline, and expelling trapped air bubbles inside the pipeline; pre-coating is completed on the pre-coating platform 12, the appearance of the pre-coated film is observed, and parameters such as glue supply flow rate, coating speed, and die head Z-axis gap are finely adjusted to calibrate the process conditions to the requirements of the formal coating process. This step is completed entirely on the pre-coating platform 12, without consuming the production substrate, and solves the problems of film thickness deviation at the starting position and uneven edge coating in traditional processes.

[0058] S4: Continuous constant-flow adhesive supply for formal coating. The large-size substrate to be coated is precisely positioned on the coating platform 13. Initially, the first injection unit 44 performs constant pressure and constant flow adhesive supply. When the first injection unit 44 is nearing the end of its stroke, the adhesive supply controller drives the second injection unit 45 to perform pressure following and flow pre-synchronization. The pressure detection module collects signals, and after the pressure and flow of the two injection units are completely consistent, the constant flow reversing valve group is activated, seamlessly switching to the second injection unit 45 to supply adhesive. The first injection unit 44 returns to perform extraction, suction, storage, and pre-pressure stabilization. The two injection units work alternately in a cycle to achieve continuous constant flow and constant pressure adhesive supply throughout the coating process. The dual servo control unit 8 is linked with the drive unit 3 to control the slit die head 4 to move at a uniform speed, completing the continuous coating of the entire substrate surface.

[0059] S5: Finishing and cyclic mass production. After the coating operation of a single substrate is completed, the glue supply controller controls the constant flow injection pump glue supply unit 7 to stop the glue supply of the two injection units, and the slit die head 4 is reset with the gantry frame 6; repeating the above S3-S5 process can realize the continuous and stable coating production of large-scale large-area substrates.

[0060] Example 6 This Example 6 is a practical application example of the structure of Example 4 for large-size perovskite photovoltaic glass substrates. The equipment hardware structure is the same as in Example 4; the marble platform 2 ensures the overall machine's reference accuracy; before each formal coating, the pre-coating platform 12 is subjected to wetting, venting, and working condition calibration processes; the constant flow injection pump glue supply unit 7 relies on the seamless switching of dual-unit pressure and flow pre-matching to eliminate slurry supply pulsation; the air flotation unit 9 ensures that the slit die head 4 moves long distances without shaking; the coating platform 13 uses zoned progressive vacuum adsorption to completely flatten the large-size perovskite glass substrate.

[0061] Workflow: The equipment completes the leveling and overall calibration of the marble platform 2; the perovskite glass substrate is loaded onto the coating platform 13, and the substrate is flattened and fixed by the zonal vacuum adsorption; the gantry frame 6 drives the slit die head 4 to move to the pre-coating platform 12 to complete lip wetting, pipeline venting, and process parameter calibration; after the parameters are verified to be qualified, the die head moves to the coating start position on the glass substrate; the dual injection units alternately and continuously supply glue, and the dual servo control units 8 control the material flow rate and the die head movement speed in a coordinated manner to complete the slit coating of the entire perovskite substrate. This embodiment can be equipped with an external automatic loading and unloading mechanism to form a fully automatic production line, completing the entire process of automatic substrate loading, coating, and unloading for mass production, effectively reducing the perovskite substrate debugging scrap rate and improving the film yield.

Claims

1. A large-area planar coating equipment, characterized in that: The system includes a frame (1), a marble platform (2) is placed on a protective base plate (15) in the frame (1), a load-bearing frame (71) is installed on the marble platform (2), and an aluminum alloy base plate (74) on the load-bearing frame (71) has three slide rails (57) arranged longitudinally. A pre-coating platform (12) and a coating platform (13) are installed on the three slide rails (57) in sequence. A gantry frame (6) is supported on the load-bearing frame (71) by an air flotation unit (9). A drive unit (3) is configured on the gantry frame (6). A thickness measuring unit (5), a slit die head (4) and an air knife unit (11) are installed in the gantry frame (6). A constant flow injection pump glue supply unit (7) and a dual servo control unit (8) are also installed on the gantry frame (6).

2. The large-area planar coating equipment according to claim 1, characterized in that: The bottom of the frame (1) is called the protective cover base (14). The four corners of the lower end face of the protective cover base (14) are respectively provided with casters, and the wheels are provided with adjustment feet. The upper end face profile of the protective cover base (14) is fixedly installed with a protective cover base plate (15). A protective cover (16) is installed upward along the perimeter of the protective cover base plate (15). A human-machine interface (10) is provided on the outer surface of the protective cover (16) at the height of the operating station.

3. The large-area planar coating equipment according to claim 1, characterized in that: The marble platform (2) is connected to the protective base plate (15) by a fixed connecting frame (18) around its perimeter. Multiple anti-vibration pads are arranged on both sides of the upper surface of the marble platform (2). Each anti-vibration pad is supported by a load-bearing frame (71) through a set of threaded leveling components (49).

4. The large-area planar coating equipment according to claim 1, characterized in that: An aluminum alloy base plate (74) is installed on the load-bearing frame (71). Marble seats (77) are installed on both sides of the aluminum alloy base plate (74) in the longitudinal direction. A grating ruler (63) is installed inside one side of the marble seat (77). A second upright plate (62) and a drive unit (3) are provided on the load-bearing frame (71) corresponding to the grating ruler (63). A reading head connector (61) is fixed on the second upright plate (62). A reading head (60) is installed on the reading head connector (61).

5. The large-area planar coating equipment according to claim 1, characterized in that: The load-bearing frame (71) has horizontal optical shafts (50) fixed longitudinally on both sides of the outer facade. The optical shafts (50) are fitted with air bearing bushings of air bearing unit (9). The air bearing bushings are fixedly connected to the air bearing mounting block (51). The air bearing mounting block (51) is fixedly connected to the upright plate (28) of the gantry frame (6). The air bearing unit (9) is composed of air bearing bushings, air bearings and matching locking components.

6. The large-area planar coating equipment according to claim 1, characterized in that: The gantry frame (6) is provided with Z-axis adjustment mechanisms at both horizontal ends. The top horizontal main beam of the gantry frame (6) includes a horizontal beam 1 (20) and a horizontal beam 2 (72) spaced side by side. A lower support (29) is fixedly connected to each end of the horizontal beam 1 (20) and the horizontal beam 2 (72). The two lower supports (29) at each end are connected to a horizontal support plate (27) downwards. A vertical plate 1 (28) is fixedly connected downwards along the outer edge of each horizontal support plate (27). The inner surface of the vertical plate 1 (28) on each side is fixedly connected to the air flotation mounting block (51). A dust-free drag chain (30) is provided on the outer facade of the vertical plate 1 (28) on one side. A gantry seat (25) is provided between the first crossbeam (20) and the second crossbeam (72). The slit mold head (4) is installed under the gantry seat (25). The two ends of the gantry seat (25) are hinged to the two sides of the slide (75) through the bearings on both sides. The back of the slide (75) is connected to the slider of the moving module (76). A cylinder seat (21) is fixed on the top of the slide (75). A cylinder (22) is hinged downward to the cylinder seat (21). The piston rod end of the cylinder (22) is fixed downward to the horizontal support plate (27) by screws.

7. The large-area planar coating equipment according to claim 1, characterized in that: The structure of the air knife unit (11) includes a top plate (38) and a connecting frame (35). Two angle plates (33) are fixedly connected downward at both ends of the top plate (38). A rotating block (32) is provided on the inner surface of the lower end of each of the two angle plates (33). An air knife (31) is fixedly connected between the two rotating blocks (32). A screw (34) is provided on the outer side of each angle plate (33). A connecting frame (35) passes through both screws (34). The two screws (34) pass upward through the connecting frame (35) and are fixedly connected to the top plate (38). The connecting frame (35) is fixedly connected to the second crossbeam (72). A limiting nut (37) is provided at the upper and lower positions of each screw (34) corresponding to the connecting frame (35). A rotating wheel (36) is also provided between each upper limiting nut (37) and the connecting frame (35).

8. The large-area planar coating equipment according to claim 1, characterized in that: The constant flow injection pump glue supply unit (7) includes two injection units, namely the first injection unit (44) and the second injection unit (45). The first injection unit (44) and the second injection unit (45) are fixedly installed on the crossbeam (20) using the injection pump base (39). It also includes a constant flow reversing valve group, a pressure detection component and a glue supply controller. The first injection unit (44) and the second injection unit (45) are arranged symmetrically in parallel. The two injection units are equipped with independent servo drive mechanisms, which can independently complete the actions of extracting and pushing materials for injection. Each injection unit is equipped with an independent glue supply unit.

9. A method for large-area planar coating, utilizing the large-area planar coating equipment according to any one of claims 1-8, characterized in that, Follow these steps: S1: Leveling of marble platform, pre-coating platform, and coating platform; S2: Equipment calibration and parameter preset; S3: Pre-coating condition calibration; S4: Continuous constant flow adhesive application for formal coating; S5: Finalization and recycle mass production After coating a single substrate, the glue supply controller stops the glue supply of the two injection units and the slit die head (4) is reset; repeat the above steps to achieve continuous and stable coating of large batches of large-area substrates multiple times.

10. The large-area planar coating method according to claim 9, characterized in that, In step S1, the specific process is as follows: the marble platform 2 is leveled by using the casters at the four corners of the lower end face of the protective base (14) and the adjusting feet between each wheel; the load-bearing frame (71) and the aluminum alloy substrate (74) are leveled by using the threaded leveling component (49) to ensure the level of the three slide rails (57) on the aluminum alloy substrate (74); and the pre-coating platform (12) and the coating platform (13) on the aluminum alloy substrate (74) are leveled by using the two sets of three sets of support components 78 set on the three slide rails (57) and the spring gap elimination components, and the triangular layout leveling method is adopted to ensure that the flatness requirements of the coating are met on the aluminum alloy substrate (74). In step S2, the specific process is as follows: the reference plane of the marble platform (2), the translation accuracy of the slit die head (4), and the working gap of the air flotation unit (9) are calibrated by the dual servo control unit (8); the target film thickness, coating speed, glue supply flow rate, dual unit switching threshold, timing / quantitative parameter process information are entered on the human-machine interface (10); the coating platform (13) is vacuum adsorbed and flattened. In step S4, the specific process is as follows: the substrate to be coated is precisely positioned on the coating platform (13), and initially the first injection unit (44) supplies the coating with constant pressure and constant flow. When the first injection unit (44) is near the end of its stroke, the glue supply controller drives the second injection unit (45) to follow the pressure and synchronize the flow. After the pressure and flow of the two units are completely consistent, the glue supply is seamlessly switched to the second injection unit (45) through the reversing valve group, and the first injection unit (44) returns to extract the stored material. The two units alternate in this way to achieve uninterrupted constant flow glue supply throughout the process. The dual servo control unit links and controls the slit die head (4) to move evenly to complete the continuous coating of the entire substrate.

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