Level meter for assisting wet etching of solar cell
By designing a level instrument to assist in the wet etching of solar cells, and using a U-tube and capillary tube to measure the height difference of the rollers, the problems of cumbersome operation and low measurement accuracy in the existing technology have been solved, thus achieving simplified operation, improved measurement accuracy and production stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2026-03-31
AI Technical Summary
Existing wet etching equipment is cumbersome to operate during calibration, requires multiple people to work together, has low testing accuracy, and poses safety hazards and production capacity losses.
Design a level instrument to assist in wet etching of solar cells. It adopts a U-shaped tube and capillary structure, and measures the height deviation between rollers by the liquid level difference in the capillary, which simplifies the operation and improves the measurement accuracy.
It achieves simple operation, high safety, and high measurement accuracy, reducing waste of human resources and production downtime, and improving production stability and product quality.
Smart Images
Figure CN224066140U_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of solar panel fabrication technology, and in particular to a level that assists in the wet etching of solar cells. Background Technology
[0002] With increasing international emphasis on new energy sources, photovoltaic power generation has gradually come into the public eye, and the market size has expanded continuously over the past decade. The entire industry chain, from upstream to downstream, is constantly innovating and breaking through technological barriers, leading to industry-wide updates and iterations. Among these, the solar cell segment, as a crucial link connecting upstream and downstream, has the highest technical threshold and precision requirements. Changes in process control and production routes often determine changes in upstream and downstream support. By the end of 2024, the industry had fully entered the N-type era, with TOPCON currently holding the largest market share, followed by heterojunction and full back contact cells.
[0003] While batteries on the market differ significantly in structure and production routes, they all involve the fabrication of key structures such as PN junctions and passivation layers. During the fabrication of these key structures, edge-wrapping plating is unavoidable in the corresponding film layer preparation. Currently, the solution for edge-wrapping plating is wet etching, which includes both tank-type and chain-type equipment. Both types operate on the same principle: using a solution to chemically or physically react with the silicon wafer to modify or clean the surface structure, resulting in a pre-designed structure. Therefore, controlling the chemical reaction process is crucial.
[0004] It's important to note that wet etching is essentially a solid-liquid reaction process between a silicon wafer and a liquid. Besides controlling core parameters such as time, component ratios, and temperature, factors like liquid flowability, solid-liquid contact effectiveness, and byproduct handling directly impact the reaction. Therefore, it is highly sensitive to controlling key parameters such as the solution circulation system inside the tank etching machine, the roller vibration amplitude of the chain etching machine, and the roller level. These are closely related to the factory environment (e.g., the level of the factory foundation, ground subsidence in mountainous factories) and the precision of the equipment, especially the chain etching machine. The chain etching machine primarily uses rotating rollers to propel the silicon wafer forward, causing the chemical solution adhering to the rollers to react with the wafer, achieving single-sided and edge etching while the other side retains its original structure. This process requires extremely precise horizontal height differences between the rollers.
[0005] During commissioning and production, this type of equipment requires frequent maintenance and adjustment of the machine level or roller height difference. The existing adjustment methods are the level gauge + tripod observation method or the laser level test method.
[0006] The most common method for calibrating the level of the chain machine rollers in a photovoltaic factory is the ruler + tripod observation method. During the calibration process, the chemical solution inside the chain machine needs to be emptied to stop the rollers from rotating. Then, a "T-shaped ruler" is placed vertically above two adjacent rollers. The deviation of the ruler is observed through a tripod observation lens at a distance. The height difference between the two rollers is adjusted and reduced according to the deviation until the level is achieved.
[0007] However, the aforementioned method of observing using a ruler and tripod requires coordination among multiple people, is very inconvenient to maintain, and has limited testing accuracy. Therefore, this proposal designs a new level observation device to overcome these problems. Summary of the Invention
[0008] The purpose of this invention is to overcome the shortcomings of the existing technology, improve the level instrument for wet etching of solar cells, and solve the problems of cumbersome operation, inconvenient maintenance, and low testing accuracy of the existing "ruler + tripod" observation method.
[0009] It should be noted that the existing "ruler + tripod" observation method has the following problems: ① The existing testing method is cumbersome to operate, requiring multiple people (at least two), one to control the ruler and the other to observe. It also requires a high level of testing skill, as tripod fixing and ruler placement can affect testing accuracy. Users need strong experience and patience. ② The testing environment is limited, which is not conducive to daily maintenance. It is necessary to drain the chemical solution inside the machine, which not only wastes resources and causes long downtime and restart time, resulting in significant production capacity loss, but also poses a safety hazard as the ruler needs to come into contact with the internal structure during testing, potentially causing injury. ③ The testing accuracy is limited, with the minimum error only reaching 1-2mm, resulting in poor production line stability and a high defect rate. As the equipment wears down during operation, frequent maintenance is required.
[0010] Based on this, the solution uses a simple level to achieve convenient operation, easy maintenance, and high observation accuracy.
[0011] The objective of this utility model is achieved through the following technical solution: a level instrument for assisting wet etching of solar cells, including a U-shaped tube;
[0012] The left and right ends of the U-shaped tube are respectively connected to a left capillary tube and a right capillary tube, and both the left and right capillary tubes have scales.
[0013] The U-shaped tube contains liquid, and the liquid also enters the left capillary and the right capillary; the left capillary and the right capillary are respectively fixed on the end face of the shaft corresponding to the adjacent rollers in the chain machine for wet etching, and after fixing, the liquid level in the left capillary and the right capillary is at the same scale position.
[0014] If the liquid levels in the left and right capillaries are not at the same height, a height deviation will occur between adjacent rollers in the chain machine used for wet surface etching.
[0015] As a preferred technical solution of this application, the U-shaped tube is provided with a liquid inlet head, which is connected to the liquid inlet pipe via a switching valve. Liquid is injected into the U-shaped tube, the left capillary tube, and the right capillary tube from the liquid inlet pipe and the liquid inlet head, maintaining a continuous liquid level in the left and right capillary tubes.
[0016] As a preferred embodiment of this application, the left and right capillaries are fixed with supports, and suction cups are provided on the supports. The left and right capillaries are fixed to the end faces of the shafts corresponding to adjacent rollers in a chain machine for wet etching by suction cups.
[0017] As a preferred technical solution of this application, the left and right ends of the U-shaped tube are connected to the left and right capillary tubes via connectors; the connectors are cap-shaped and are screwed onto the left and right ends of the U-shaped tube; the connectors have rubber tubes running through them, and the corresponding left and right capillary tubes are inserted into the rubber tubes.
[0018] Furthermore, a filter element is embedded inside the lower end of the rubber tube.
[0019] Furthermore, the left and right capillary tubes are fitted with sealing rings and then inserted into the rubber tube, and are fixed with glue.
[0020] As a preferred embodiment of this application, the upper ends of the left and right capillary tubes are detachably screwed with auxiliary caps. The auxiliary caps are removed during normal operation and screwed back on when readings are required.
[0021] To facilitate understanding, the working process and principles of this solution will be explained as follows:
[0022] When a chain machine used for wet etching of solar panels is used for a long time, the bearings of the rollers in the chain machine will wear down, resulting in height differences between the rollers. This will seriously affect the wet etching effect of the solar panels and thus the quality of the solar panels. (The chain machine has multiple rollers spaced apart on a horizontal plane. Solar panels are placed on the rollers. The chain machine is filled with etching solution, and there is a protective solution on top of the etching solution. The separation line between the etching solution and the protective solution is located at the axis of the rollers. The lower part of the roller is in the etching solution and the upper part of the roller is in the protective solution. When the rollers rotate, the rollers will carry a part of the etching solution to contact the bottom surface of the solar panel, thus achieving etching. If the height difference between adjacent rollers is not the same, the etching condition of the bottom of the solar panel will be different, thus affecting the etching effect of the solar panel.)
[0023] Since the two ends of the rotating shafts of each roller in the chain conveyor extend outside the housing (through bearings and sealed installation), this design fixes the left and right capillary tubes to the end faces of the rotating shafts of adjacent rollers using suction cups. Liquid is injected into the U-shaped tube and the left and right capillary tubes—and initially, the liquid levels in the left and right capillary tubes are kept consistent. When there is a height difference between adjacent rollers, the U-shaped tube and the left and right capillary tubes will tilt to a certain extent. Using the principle of communicating vessels, the liquid levels in the left and right capillary tubes are always at the same level. However, after tilting, the scale corresponding to the liquid level in the left capillary tube is inconsistent with the scale corresponding to the liquid level in the right capillary tube. Therefore, the height difference between the two rollers can be calculated by the scale difference.
[0024] This utility model has the following advantages:
[0025] (1) Easy to operate;
[0026] The existing observation method of "ruler + tripod" is cumbersome to operate and requires the cooperation of multiple people (at least two people). One person controls the ruler and the other observes. It also requires high testing skills. The tripod fixing / ruler placement will affect the test accuracy. Users need to have strong experience and patience.
[0027] In this solution, the left and right capillary tubes are fixed with suction cups at the detection point positions on the end faces of the corresponding rotating shafts of adjacent rollers. Then, the results can be obtained by visual observation and simple calculation. The operation is very simple and convenient (with low requirements for personnel professionalism).
[0028] (2) Not limited by the testing environment, and easy to maintain;
[0029] The existing observation method of "ruler + tripod" requires the chemical liquid inside the machine to be emptied, which not only wastes resources and has a long downtime and restart time, resulting in a large loss of production capacity, but also the chemical is acidic, and the ruler needs to come into contact with the internal structure during the test, which poses a safety hazard and may cause personnel injury.
[0030] In this solution, the end faces of the rotating shafts of adjacent rollers are located outside the chain machine, eliminating the need to remove the internal chemical solution, thus making it very convenient to maintain the precision of the chain machine rollers;
[0031] (3) High testing accuracy;
[0032] The existing observation method of "ruler + tripod" can only achieve a minimum error of 1-2mm, resulting in poor production line stability and a high defect rate. As the equipment wears out during operation, the ruler itself also needs to be maintained frequently.
[0033] In this design, even slight changes in height can be accurately reflected by the capillary scale, resulting in high measurement precision. Attached Figure Description
[0034] Figure 1 This is a schematic diagram of the structure of this utility model;
[0035] Figure 2 A schematic diagram of a T-shaped scale on the rollers of a chain conveyor.
[0036] Figure 3 This is a schematic diagram of a tripod observation mirror;
[0037] Figure 4 This is a schematic diagram of etching a solar panel in a chain machine.
[0038] In the diagram: 10-U-shaped tube, 11-connector, 12-rubber tube, 13-filter element, 14-sealing ring, 20-left capillary tube, 21-right capillary tube, 22-support, 23-suction cup, 24-auxiliary cover, 30-liquid inlet head, 31-switch valve;
[0039] 40 - Roller, 50 - T-shaped scale, 60 - Tripod observation mirror. Detailed Implementation
[0040] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.
[0041] It should be noted that the orientation or positional relationship indicated by terms such as "left" and "right" is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of this utility model is usually placed in during use, or the orientation or positional relationship that is commonly understood by those skilled in the art. Such terms are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0042] It should be noted that, in existing related technologies, reference Figure 4 As shown, during wet etching of solar panels, the panels are placed on rollers arranged side-by-side in a chain machine. Inside the chain machine, there is an etching solution, with a protective solution on top. When the panels are placed on the rollers, the entire panel is submerged in the protective solution, with the lower part of the rollers submerged in the etching solution and the upper part submerged in the protective solution. When the rollers rotate, the cylindrical surfaces with the etching solution adhering to them rotate to the upper position, allowing the etching solution to contact the lower surface of the panel for etching. Then, due to the higher density of the etching solution (compared to the protective solution), the etching solution falls back down after a certain degree of etching.
[0043] During the etching process, the horizontal height difference between the rollers in the chain machine is extremely critical (affecting the etching quality of the solar panel, and thus the quality of the solar panel). Therefore, it is necessary to ensure that the horizontal height difference between the rollers is within a suitable range.
[0044] In existing technologies, the most common method for calibrating the level of chain conveyor rollers in photovoltaic factories is the "ruler + tripod" observation method. The specific procedure is as follows: (Refer to...) Figure 2 and Figure 3 During the calibration process, the chemical solution in the chain machine needs to be drained to stop the roller 40 from rotating. The "T-shaped scale" 50 is placed above the two adjacent rollers, and the deviation of the "T-shaped scale" 50 is observed through the tripod observation lens 60 at a distance. The height difference between the two rollers is adjusted and reduced according to the observed deviation until it reaches a horizontal position.
[0045] However, the existing "ruler + tripod" observation method has the following problems: ① The existing testing method is cumbersome to operate, requiring multiple people (at least two people) to work together, one to control the ruler and the other to observe. It also requires high testing skills, as tripod fixing and ruler placement can affect testing accuracy, requiring users to have strong experience and patience; ② The testing environment is limited, which is not conducive to daily maintenance. It is necessary to drain the chemical liquid inside the machine, which not only wastes resources and causes long downtime and restart time, resulting in significant production capacity loss, but also the fact that the chemical is acidic, and the ruler needs to come into contact with the internal structure during testing, posing a safety hazard and causing personnel injury; ③ The testing accuracy is limited, with the minimum error only reaching 1-2mm, resulting in poor production line stability, a high defect rate, and frequent maintenance as the equipment wears down.
[0046] Based on this, this solution provides the following approach: by setting a U-shaped tube with graduated capillary tubes at both ends, and fixing the capillary tubes at both ends to adjacent rollers in an adjacent chain machine, if there is a height difference between adjacent rollers, it can be reflected by the graduations on the capillary tubes, and the value can be read quickly, which is very simple and convenient.
[0047] The following provides a specific implementation method for this solution.
[0048] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.
[0049] See Figure 1 This embodiment provides a leveling instrument to assist in wet etching of solar cells, including a U-shaped tube 10;
[0050] A left capillary tube 20 and a right capillary tube 21 are connected to the left and right ends of the U-shaped tube 10, respectively, and both the left capillary tube 20 and the right capillary tube 21 have scales.
[0051] In addition, the U-shaped tube 10 is filled with liquid, and the liquid also enters the left capillary tube 20 and the right capillary tube 21;
[0052] During installation, the left capillary tube 20 and the right capillary tube 21 are respectively fixed on the end face of the shaft corresponding to the adjacent rollers in the chain machine for wet etching, and after fixing, the liquid level in the left capillary tube 20 and the right capillary tube 21 is at the same scale position.
[0053] During the observation process, if the liquid levels of the left capillary 20 and the right capillary 21 are not at the same height, a height deviation will occur between the adjacent rollers in the chain machine used for wet surface etching. In the specific calculation, the scale value corresponding to the liquid level of one capillary is subtracted from the scale value corresponding to the liquid level of the other capillary, and then divided by 2 and the absolute value is taken to obtain the height difference between the two adjacent rollers, which is very simple and convenient.
[0054] Furthermore, since the rotating shaft corresponding to the roller in the prior art extends outside the housing of the chain machine (installed with bearings and equipped with a sealing mechanism), this solution fixes the right capillary tube 20 and the right capillary tube 21 to the end face of the rotating shaft of the corresponding roller. Therefore, during the observation and calculation process, it is not necessary to drain the chemical solution (etching solution, protective solution) inside the chain machine.
[0055] Therefore, it can be said that this observation method simply requires fixing the corresponding capillary tube to the end face of the roller's rotating shaft, allowing for observation and calculation, which is very simple and convenient. Compared to the traditional "ruler + tripod" method, this method does not require emptying the chemical solution (the testing environment is not harsh), the testing method is simple (the requirements for personnel professionalism are not high), and the scale on the capillary tube can accurately reflect the height difference (the accuracy is higher than that obtained by tripod observation).
[0056] In this embodiment, the left capillary 20 and the right capillary 21 are made of materials such as quartz or glass, with a volume capacity of 1-10 μL. The outer side is marked with graduations that increase sequentially from bottom to top, with the smallest graduation unit being 0.1 μL. The inner diameter uniformity tolerance is less than ±1 μm, and the surface roughness Ra≤0.05 μm, ensuring good liquid flowability.
[0057] In this embodiment, the U-shaped pipe 10 is made of materials such as polypropylene (PP) and polyvinyl chloride (PVC). The pipe diameter and length can be changed according to the actual application scenario. The pipe diameter is matched with the lower end of the pipe union. Smaller pipe diameter and shorter length are preferred, which is beneficial for weight reduction.
[0058] The structure of the liquid entering the U-shaped tube 10 will be further explained below.
[0059] A liquid inlet head 30 is provided on the U-shaped tube 10, and the liquid inlet head 30 is connected to the liquid inlet pipe via a switch valve 31; the liquid inlet pipe is connected to the storage tank via a pump. During operation, liquid is injected from the liquid inlet pipe and the liquid inlet head 30 into the U-shaped tube 10 and the left capillary tube 20 and the right capillary tube 21, maintaining a continuous liquid level in the left capillary tube 20 and the right capillary tube 21.
[0060] The mounting structure of the corresponding capillary tube and the chain machine for wet etching will be further explained below.
[0061] A bracket 22 is fixed on the left capillary tube 20 and the right capillary tube 21, and a suction cup 23 is provided on the bracket 22. During installation, the left capillary tube 20 and the right capillary tube 21 are fixed to the end face of the corresponding shaft of the adjacent roller in the chain machine for wet etching by suction cup 23.
[0062] Furthermore, the suction cup 23 is made of rubber or magnetic material, with good surface flatness and adhesion requirements. It can be disassembled and replaced according to the application scenario and fixed to the bracket 22 by screws or rivets.
[0063] The following further explains the installation method between the U-shaped tube 10 and the corresponding capillary tubes. The left and right ends of the U-shaped tube 10 are connected to the left capillary tube 20 and the right capillary tube 21 via connectors 11. The connectors 11 are cap-shaped and are screwed onto the left and right ends of the U-shaped tube 10; the connectors 11 have rubber tubes 12 that pass through from top to bottom, and the corresponding left capillary tube 20 and right capillary tube 21 are inserted into the rubber tubes 12.
[0064] Furthermore, a filter element 13 is embedded inside the lower end of the rubber tube 12. After sealing rings 14 are fitted onto the left capillary tube 20 and the right capillary tube 21, they are inserted into the rubber tube 12 and fixed with glue.
[0065] The readings of the corresponding capillary tubes are further explained below. The upper ends of the left capillary tube 20 and the right capillary tube 21 are detachably screwed with auxiliary caps 24 via threads; the auxiliary caps 24 are removed during normal operation and screwed on when readings are required.
[0066] The working process of the level in this embodiment is described below:
[0067] (1) First, perform calibration: After the storage tank is connected to the inlet pipe, fix the left capillary tube 20 and the right capillary tube 21 vertically to any wall surface through the suction cup 23. Keep the fixed height of the two capillary tubes as uniform as possible. Open the switch valve 31 and inject ultrapure water into the U-shaped tube 10 through the inlet pipe. Let the liquid pass through the filter element 13 into the left capillary tube 20 and the right capillary tube 21 so that the liquid level reaches 1 / 3 of the volume of the two capillary tubes. Close the switch valve 31, check the sealing performance, and record the readings of the two capillary tubes. After standing for a period of time, record the readings of the two micro-capillary tubes again. Only when the two readings are consistent can the micro-capillary tube level tester be removed and the test can begin. After this first step is completed, subsequent tests only need to check the sealing performance.
[0068] (2) Conduct actual testing: First, fix the left capillary 20 and the right capillary 21 vertically to the test point (the point marked in advance on the end face of the rotating shaft of the two adjacent rollers of the chain machine) through the suction cup 23. After waiting for 5-10 seconds for the liquid level to stabilize, read the readings A and B of the two micro-lift capillary tubes respectively. The difference in readings is used to obtain the difference in the horizontal height of the test point as |AB| / 2. The point with the larger reading is lower and needs to be adjusted to rise. Repeat the adjustment of the roller position until the readings of the two micro-lift capillary tubes are consistent. The minimum scale of the micro-lift capillary tube is 0.1μL. The reading error is less than 0.1μL and the height horizontal error can be less than 0.22mm.
[0069] It should be noted that the level tester in this solution is portable and the measurement points and distances are relatively flexible (the length of the U-tube 10 and the distance between the left and right ends of the U-tube can be selected according to the needs of the corresponding U-tube 10--thus corresponding test points at the corresponding distance), which can be used as a routine inspection method in the factory.
[0070] The above embodiments only illustrate preferred implementation methods, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.
Claims
1. A level for assisting wet etching of solar cells, characterized in that: It comprises a U-shaped tube (10); The left and right ends of the U-shaped tube (10) are connected with a left capillary tube (20) and a right capillary tube (21) respectively, and the left capillary tube (20) and the right capillary tube (21) are provided with scales; The U-shaped tube (10) is filled with liquid, and the liquid also enters the left capillary tube (20) and the right capillary tube (21); the left capillary tube (20) and the right capillary tube (21) are fixed on the end faces of the shafts corresponding to the adjacent rollers in the chain machine for wet etching, and the liquid levels in the left capillary tube (20) and the right capillary tube (21) are located at the same scale position after being fixed; If the liquid levels of the left capillary tube (20) and the right capillary tube (21) are not at the same height, there is a height deviation between the adjacent rollers in the chain machine for wet etching.
2. The level for aiding wet etching of solar cells according to claim 1, wherein: The U-shaped tube (10) is provided with a liquid inlet head (30), and the liquid inlet head (30) is connected with a liquid inlet pipe through a switch valve (31); Liquid is injected into the U-shaped tube (10) and the left capillary tube (20) and the right capillary tube (21) from the liquid inlet pipe and the liquid inlet head (30), so that the left capillary tube (20) and the right capillary tube (21) continuously maintain liquid.
3. The level to assist wet etching of solar cells according to claim 1, wherein: The left capillary tube (20) and the right capillary tube (21) are fixed with a support (22), and the support (22) is provided with a suction cup (23); The left capillary tube (20) and the right capillary tube (21) are fixed on the end faces of the shafts corresponding to the adjacent rollers in the chain machine for wet etching through the suction cup (23).
4. The level to assist wet etching of solar cells according to claim 1, wherein: The left and right ends of the U-shaped tube (10) are connected with the left capillary tube (20) and the right capillary tube (21) through a connecting head (11); The connecting head (11) is in the form of a cap, which is screwed on the left and right ends of the U-shaped tube (10); the connecting head (11) is provided with a rubber pipe (12) penetrating from top to bottom, and the left capillary tube (20) and the right capillary tube (21) are inserted into the rubber pipe (12).
5. The level to assist wet etching of solar cells according to claim 4, wherein: The lower end of the rubber pipe (12) is embedded with a filter core (13).
6. The level to assist wet etching of solar cells according to claim 4, wherein: The left capillary tube (20) and the right capillary tube (21) are inserted into the rubber pipe (12) after being sleeved with a sealing ring (14), and are fixed by glue.
7. The level to assist wet etching of solar cells according to claim 1, wherein: The upper end of the left capillary tube (20) and the right capillary tube (21) is detachably screwed with an auxiliary cover (24) through threads; The auxiliary cover (24) is removed during normal operation, and is screwed on when reading is needed.