Photoetching alignment method and system for photovoltaic cell and mask plate
By automatically calculating the standard exposure position through visual inspection, the problem of cumbersome and inaccurate photolithography alignment steps for photovoltaic cells has been solved, achieving efficient and accurate photolithography alignment and reducing hardware costs and time consumption.
Patent Information
- Application Number
- CN202511407004.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2025-12-16
AI Technical Summary
In existing technologies, the photolithography alignment process for photovoltaic cells is cumbersome, relies heavily on manual operation, and cannot guarantee accuracy, resulting in insufficient overlay precision.
By automatically calculating the standard exposure position through visual inspection, combined with camera shooting and calculation, high-precision alignment of photovoltaic cells and photomasks can be achieved, reducing manual intervention.
It achieves fast and accurate photolithography alignment, reduces hardware costs and time consumption, and improves overlay accuracy.
Smart Images
Figure CN121149080A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photovoltaic cell technology, and in particular to a photolithographic alignment method and system for photovoltaic cells and photomasks. Background Technology
[0002] Currently, photovoltaic (PV) cells are manufactured using screen printing, where silver paste is transferred onto the cell in a pattern, and then sintered at high or low temperatures to form silver electrodes as conductors. This method is simple and is the most widely used metallization method for PV cells in mass production. In recent years, the width and aspect ratio of silver electrodes in screen printing have approached their limits, but the expensive silver paste used in this process prevents further reductions in PV cell production costs. To reduce PV cell costs while improving efficiency, a patterned electroplating metallization method has emerged to create metal electrodes for the cells. This method allows the use of cheaper copper instead of silver, reducing costs and enabling increasingly thinner conductors, thus improving the cell's power generation efficiency.
[0003] Photolithography, as a step in the patterning process, is one of the most critical steps in patterning, determining the linewidth, lineheight, and morphology of the pattern subsequently electroplated. Exposure involves using a parallel ultraviolet light source to illuminate a photomask. The photomask has transparent and opaque areas depending on the customized pattern. The parallel light passes through the transparent areas of the photomask and illuminates the solar cell, causing a photoresist chain reaction in the illuminated areas. Subsequent development then transfers the pattern onto the solar cell, achieving the patterning purpose.
[0004] After photolithography, the pattern on the solar cell is located in the center of the cell, with a slight distance between the outermost lines and the edge. This necessitates a certain level of overlay precision. In practical use, the mask position changes with each replacement, affecting the pattern position. Furthermore, the position of each solar cell on the exposure stage varies after it is attached. In short, improving the accuracy of photovoltaic cell photolithography alignment is crucial. Another challenge in photovoltaic cell photolithography alignment is the inability to create alignment marks on the cell surface, making it impossible to use common methods of aligning and overlapping graphic positioning marks.
[0005] Existing technologies for finding exposure standard positions typically involve cumbersome steps, rely heavily on manual operation, and cannot guarantee accuracy. Therefore, how to quickly and accurately establish lithographic standard positions in visual alignment lithography to achieve high-precision overlay between the mask and the solar cell is a key technical challenge in photovoltaic cell lithography. Summary of the Invention
[0006] Therefore, the technical problem to be solved by the present invention is to overcome the problems of the existing technology, such as the cumbersome steps of finding the exposure standard position, the need for a lot of manual operation, and the inability to guarantee accuracy.
[0007] To address the aforementioned technical problems, this invention provides a photolithographic alignment method for photovoltaic cells and photomasks, comprising:
[0008] Step S1: Place the photovoltaic cell to be photolithographically etched at the center of the stage, move the stage below the photomask, and take pictures of the edge of the photomask and the edge of the photovoltaic cell using the first camera;
[0009] Step S2: Based on the edge information of the photomask and the photovoltaic cell captured by the first camera, obtain the positions of the photovoltaic cell and the photomask;
[0010] Step S3: Calculate the distance between the photovoltaic cell and the photomask based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask;
[0011] Step S4: The center point position of the photovoltaic cell is obtained by taking pictures and calculating using the second camera;
[0012] Step S5: Calculate the standard exposure position based on the center point of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern set on the photomask. The standard exposure position is the position where the photomask is used to transfer the pattern onto the photovoltaic cell.
[0013] In one embodiment of the present invention, step S2, which obtains the positions of the photovoltaic cell and the photomask based on the edge information of the photomask and the photovoltaic cell captured by the first camera, includes:
[0014] The location of the photovoltaic cells was obtained by taking pictures with the first camera. and the position of the mask ;
[0015] in, The coordinates of the feature points of the photovoltaic cell in the field of view of the first camera. The angle between the edge of the photovoltaic cell and the horizontal line in the field of view of the first camera. Let be the coordinates of the mask feature points in the field of view of the first camera. The angle between the edge of the mask and the horizontal line in the field of view of the first camera;
[0016] according to and Calculate the angle between the photovoltaic cell and the photomask. The formula is:
[0017] .
[0018] In one embodiment of the present invention, step S3 calculates the distance between the photovoltaic cell and the photomask based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask, using the following formula:
[0019] ];
[0020] ];
[0021] in, This refers to the horizontal distance between the photovoltaic cell and the photomask. This refers to the vertical distance between the photovoltaic cell and the photomask. This is the center position of the stage.
[0022] In one embodiment of the present invention, the method for obtaining the position information of the photovoltaic cell by capturing images with a second camera in step S4 includes:
[0023] A second camera is used to capture images of two opposite corners of the photovoltaic cell. A rectangular photovoltaic cell is then fitted using these two corners. The two diagonals of the rectangular photovoltaic cell are obtained, and the intersection of these two diagonals is taken as the center point of the photovoltaic cell. , Represented as ,in, The coordinates of the center point of the battery cell in the field of view of the second camera are: The angle between the edge of the photovoltaic cell and the horizontal line in the field of view of the second camera.
[0024] In one embodiment of the present invention, step S5 calculates the marked exposure position based on the center point position of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern disposed on the photomask, using the following formula:
[0025] Let the standard exposure position be S. Xs Ys Rs ,but:
[0026] ;
[0027] ;
[0028] ;
[0029] in, The coordinates of the standard exposure position for photovoltaic cells. The horizontal distance between the pattern and the edge of the photomask. This is the vertical distance between the pattern and the edge of the photomask.
[0030] In one embodiment of the present invention, the method further includes the following after step S5:
[0031] The difference between the actual position of the incoming photovoltaic cell and the standard exposure position is calculated. The difference guides the correction stage to move the stage, so that the photovoltaic cell and the photomask are aligned for photolithography.
[0032] In one embodiment of the present invention, the edges of the mask and the photovoltaic cell in step S1 include:
[0033] The vertical edge of the photomask and the vertical edge of the photovoltaic cell, or the horizontal edge of the photomask and the horizontal edge of the photovoltaic cell.
[0034] To address the aforementioned technical problems, this invention provides a photolithographic alignment system for photovoltaic cells and photomasks, comprising:
[0035] Placement and imaging module: used to place the photovoltaic cell to be photolithographically etched at the center of the stage, move the stage to below the photomask, and photograph the edge of the photomask and the edge of the photovoltaic cell through the first camera;
[0036] Position acquisition module: used to obtain the positions of the photovoltaic cells and the photomask based on the edge information of the photomask and the photovoltaic cells captured by the first camera;
[0037] Calculation module: used to calculate the distance between the photovoltaic cell and the photomask based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask;
[0038] The image capture and calculation module is used to capture images of the photovoltaic cells using a second camera and calculate the center point position of each cell.
[0039] Exposure position determination module: used to calculate the standard exposure position based on the center point of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern set on the photomask. The standard exposure position is the position where the photomask is used to transfer the pattern onto the photovoltaic cell.
[0040] To address the aforementioned technical problems, the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps described above for the photolithographic alignment method between a photovoltaic cell and a photomask.
[0041] To address the aforementioned technical problems, the present invention provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps described above for the photolithographic alignment method between a photovoltaic cell and a photomask.
[0042] The technical solution of the present invention has the following advantages compared with the prior art:
[0043] The photolithographic alignment method for photovoltaic cells and photomasks constructed in this invention automatically calculates the standard exposure position offset value through visual inspection and feeds it back to the exposure device (specifically to the correction stage), which is fast and highly accurate.
[0044] This invention combines the advantages of both manual and automated methods, significantly reducing camera hardware costs, shortening the time required to set the standard position, and directly quantifying the parameters for manual position adjustment, thus achieving high-precision standard position setting. Attached Figure Description
[0045] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0046] Figure 1 This is a flowchart of the method of the present invention;
[0047] Figure 2 This is a schematic diagram showing the positions of the photomask and photovoltaic cells in an embodiment of the present invention;
[0048] Figure 3 This is a schematic diagram of the angle between the edge of the photovoltaic cell and the horizontal line, and the angle between the edge of the photomask and the horizontal line in an embodiment of the present invention. Detailed Implementation
[0049] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.
[0050] Example 1
[0051] Reference Figure 1 As shown, this invention relates to a photolithographic alignment method for photovoltaic cells and photomasks, comprising:
[0052] Step S1: Place the photovoltaic cell to be photolithographically etched at the center of the stage, move the stage below the photomask, and take pictures of the edge of the photomask and the edge of the photovoltaic cell using the first camera;
[0053] Step S2: Based on the edge information of the photomask and the photovoltaic cell captured by the first camera, obtain the positions of the photovoltaic cell and the photomask;
[0054] Step S3: Calculate the distance between the photovoltaic cell and the photomask based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask;
[0055] Step S4: The center point position of the photovoltaic cell is obtained by taking pictures and calculating using the second camera;
[0056] Step S5: Calculate the standard exposure position based on the center point of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern set on the photomask. The standard exposure position is the position where the photomask is used to transfer the pattern onto the photovoltaic cell.
[0057] The following is a detailed description of this embodiment:
[0058] Further, in this embodiment, step S2, based on the edge information of the photomask and the photovoltaic cell captured by the first camera, obtains the positions of the photovoltaic cell and the photomask, including:
[0059] The location of the photovoltaic cells was obtained by taking pictures with the first camera. and the position of the mask ,in, The coordinates of the feature points of the photovoltaic cell in the field of view of the first camera (take the corner position of the photovoltaic cell, for example...) Figure 2 Take a point at the bottom left corner of the photovoltaic cell. The angle between the edge of the photovoltaic cell and the horizontal line in the field of view of the first camera. The coordinates of the mask feature points in the field of view of the first camera are taken as the corner points of the mask. Figure 2 Take a point at the bottom left corner of the mask. The angle between the edge of the mask and the horizontal line in the field of view of the first camera.
[0060] In this embodiment, the edges of the photomask and the photovoltaic cell include: the vertical edge of the photomask and the vertical edge of the photovoltaic cell, or the horizontal edge of the photomask and the horizontal edge of the photovoltaic cell.
[0061] according to and Calculate the angle between the photovoltaic cell and the photomask. (the included angle) This can be understood as the angle difference between the photovoltaic cell and the photomask. The formula is:
[0062] .
[0063] It should be noted that you should refer to [link / reference]. Figure 3In practice, the photomask and photovoltaic cells cannot be placed perfectly horizontally, so it is necessary to calculate the angle between the edge of the photovoltaic cell and the horizontal line. The angle between the edge of the mask and the horizontal line Therefore, the difference angle between the two can be obtained. .
[0064] Furthermore, in step S3 of this embodiment, the distance between the photovoltaic cell and the photomask is calculated based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask. The formula is as follows:
[0065] ];
[0066] ];
[0067] in, This refers to the horizontal distance between the photovoltaic cell and the photomask. This refers to the vertical distance between the photovoltaic cell and the photomask. This is the center position of the stage.
[0068] Furthermore, the method for obtaining the position information of the photovoltaic cells by capturing images with a second camera and calculating them in step S4 of this embodiment includes:
[0069] A second camera is used to capture images of two opposite corners of the photovoltaic cell. A rectangular photovoltaic cell is then fitted using these two corners. The two diagonals of the rectangular photovoltaic cell are obtained, and the intersection of these two diagonals is taken as the center point of the photovoltaic cell. , represented as ,in, The coordinates of the center point of the battery cell in the field of view of the second camera are: This represents the angle between the edge of the photovoltaic cell and the horizontal line in the field of view of the second camera. It should be noted that... and This is not repeated because R1 is the angle of the photovoltaic cell in the first camera, and R4 is the angle of the photovoltaic cell in the second camera.
[0070] It should be noted that in this embodiment, both the first camera and the second camera are CCD industrial vision cameras. When the second camera in step S4 is shooting the two diagonal vertices of the photovoltaic cell, one second camera (with a larger field of view) or two second cameras (with a smaller field of view) can be used depending on the field of view of the second camera. The specific number of second cameras used depends on the actual situation.
[0071] Further, please refer to Figure 2In this embodiment, step S5 calculates the marked exposure position based on the center point of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern set on the photomask. The formula is:
[0072] Let the standard exposure position be ,but:
[0073] ;
[0074] ;
[0075] ;
[0076] in, The coordinates of the standard exposure position of the photovoltaic cell (taking the corner position). The horizontal distance between the pattern and the edge of the photomask. The vertical distance between the pattern and the edge of the photomask. , The parameters are known.
[0077] Furthermore, this embodiment also includes the following after step S5:
[0078] The difference between the actual position of the incoming photovoltaic cell and the standard exposure position is calculated. The difference guides the correction stage to move the stage, so that the photovoltaic cell and the photomask are aligned for photolithography.
[0079] Furthermore, in step S1 of this embodiment, the edges of the photomask and the photovoltaic cell include:
[0080] The vertical edge of the photomask and the vertical edge of the photovoltaic cell, or the horizontal edge of the photomask and the horizontal edge of the photovoltaic cell.
[0081] This invention only needs to be performed once when the mask is replaced or the standard injection exposure position is lost. This process can be shielded in other production processes, thereby improving production efficiency.
[0082] Example 2
[0083] This embodiment provides a photolithographic alignment system for photovoltaic cells and photomasks, including:
[0084] Placement and imaging module: used to place the photovoltaic cell to be photolithographically etched at the center of the stage, move the stage to below the photomask, and photograph the edge of the photomask and the edge of the photovoltaic cell through the first camera;
[0085] Position acquisition module: used to obtain the positions of the photovoltaic cells and the photomask based on the edge information of the photomask and the photovoltaic cells captured by the first camera;
[0086] Calculation module: used to calculate the distance between the photovoltaic cell and the photomask based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask;
[0087] The image capture and calculation module is used to capture images of the photovoltaic cells using a second camera and calculate the center point position of each cell.
[0088] Exposure position determination module: used to calculate the standard exposure position based on the center point of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern set on the photomask. The standard exposure position is the position where the photomask is used to transfer the pattern onto the photovoltaic cell.
[0089] Example 3
[0090] This embodiment provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the photolithographic alignment method for photovoltaic cells and photomasks described in Embodiment 1.
[0091] Example 4
[0092] This embodiment provides a computer-readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it implements the steps of the photolithographic alignment method for photovoltaic cells and photomasks described in Embodiment 1.
[0093] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.
[0094] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0095] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0096] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0097] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0098] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A photolithographic alignment method for photovoltaic cells and photomasks, characterized in that: include: Step S1: Place the photovoltaic cell to be photolithographically etched at the center of the stage, move the stage below the photomask, and take pictures of the edge of the photomask and the edge of the photovoltaic cell using the first camera; Step S2: Based on the edge information of the photomask and the photovoltaic cell captured by the first camera, obtain the positions of the photovoltaic cell and the photomask; Step S3: Calculate the distance between the photovoltaic cell and the photomask based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask; Step S4: The center point position of the photovoltaic cell is obtained by taking pictures and calculating using the second camera; Step S5: Calculate the standard exposure position based on the center point of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern set on the photomask. The standard exposure position is the position where the photomask is used to transfer the pattern onto the photovoltaic cell.
2. The photolithographic alignment method for photovoltaic cells and photomasks according to claim 1, characterized in that: Step S2, based on the edge information of the photomask and the photovoltaic cell captured by the first camera, obtains the positions of the photovoltaic cell and the photomask, including: The location of the photovoltaic cells was obtained by taking pictures with the first camera. and the position of the mask ; in, The coordinates of the feature points of the photovoltaic cell in the field of view of the first camera. The angle between the edge of the photovoltaic cell and the horizontal line in the field of view of the first camera. Let these be the coordinates of the mask feature points within the field of view of the first camera. The angle between the edge of the mask and the horizontal line in the field of view of the first camera; according to and Calculate the angle between the photovoltaic cell and the photomask. The formula is: 。 3. The photolithographic alignment method for photovoltaic cells and photomasks according to claim 2, characterized in that: Step S3 calculates the distance between the photovoltaic cell and the photomask based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask. The formula is: ]； ]； in, This refers to the horizontal distance between the photovoltaic cell and the photomask. This refers to the vertical distance between the photovoltaic cell and the photomask. This is the center position of the stage.
4. The photolithographic alignment method for photovoltaic cells and photomasks according to claim 3, characterized in that: The method for obtaining the position information of the photovoltaic cells by capturing and calculating the image using the second camera in step S4 includes: A second camera is used to capture images of two opposite corners of the photovoltaic cell. A rectangular photovoltaic cell is then fitted using these two corners. The two diagonals of the rectangular photovoltaic cell are obtained, and the intersection of these two diagonals is taken as the center point of the photovoltaic cell. , Represented as ,in, The coordinates of the center point of the battery cell in the field of view of the second camera are: The angle between the edge of the photovoltaic cell and the horizontal line in the field of view of the second camera.
5. The photolithographic alignment method for photovoltaic cells and photomasks according to claim 4, characterized in that: Step S5 calculates the marked exposure position based on the center point of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern set on the photomask. The formula is as follows: Let the standard exposure position be ,but: ； ； ； in, The coordinates of the standard exposure position for photovoltaic cells. The horizontal distance between the pattern and the edge of the photomask. This is the vertical distance between the pattern and the edge of the photomask.
6. The photolithographic alignment method for photovoltaic cells and photomasks according to claim 5, characterized in that: Following step S5, the following is also included: The difference between the actual position of the incoming photovoltaic cell and the standard exposure position is calculated. The difference guides the correction stage to move the stage, so that the photovoltaic cell and the photomask are aligned for photolithography.
7. The photolithographic alignment method for photovoltaic cells and photomasks according to claim 1, characterized in that: The edges of the photomask and the photovoltaic cells in step S1 include: The vertical edge of the photomask and the vertical edge of the photovoltaic cell, or the horizontal edge of the photomask and the horizontal edge of the photovoltaic cell.
8. A photolithographic alignment system for photovoltaic cells and photomasks, characterized in that: include: Placement and imaging module: used to place the photovoltaic cell to be photolithographically etched at the center of the stage, move the stage to below the photomask, and photograph the edge of the photomask and the edge of the photovoltaic cell through the first camera; Position acquisition module: used to obtain the positions of the photovoltaic cells and the photomask based on the edge information of the photomask and the photovoltaic cells captured by the first camera; Calculation module: used to calculate the distance between the photovoltaic cell and the photomask based on the center position of the stage, the position of the photovoltaic cell, and the position of the photomask; The image capture and calculation module is used to capture images of the photovoltaic cells using a second camera and calculate the center point position of each cell. Exposure position determination module: used to calculate the standard exposure position based on the center point of the photovoltaic cell, the distance between the photovoltaic cell and the photomask, and the distance between the photomask and the pattern set on the photomask. The standard exposure position is the position where the photomask is used to transfer the pattern onto the photovoltaic cell.
9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the steps of the photolithographic alignment method for photovoltaic cells and photomasks as described in any one of claims 1 to 7.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, it implements the steps of the photolithographic alignment method for photovoltaic cells and photomasks as described in any one of claims 1 to 7.