A method for manufacturing a solar cell
By using the printing technology of insulating photoresist and ink mask layer in solar cell production, the problems of high difficulty and high cost of photolithography process have been solved, achieving simpler and lower cost production and improving production yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-23
- Publication Date
- 2026-06-23
AI Technical Summary
In the current solar cell production process, the photolithography process using proximity exposure is difficult to operate, costly, and requires a high level of environmental cleanliness. It is also prone to pattern defects caused by dust or impurities, which affects the production yield.
An insulating photoresist layer is formed on the surface of a silicon substrate, and a grid pattern is formed on it by printing an ink mask layer, instead of the traditional mask proximity exposure. The cross-linking and curing properties of the negative photoresist are used for development to form grid grooves and electroplated metal grid lines.
It simplifies the process, reduces production costs, significantly improves product yield, and avoids the contamination risk of photomask proximity exposure.
Smart Images
Figure CN122269854A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photovoltaic technology, and more specifically, to a method for preparing a solar cell. Background Technology
[0002] Currently, the electroplating process in solar cell production typically includes: depositing a metal seed layer on the surface of a silicon substrate, coating it with photoresist, performing patterned exposure and development using a photolithography process combined with a mask to form grid grooves, and then performing electroplating to grow grid lines within the grid grooves.
[0003] Current photolithography processes generally employ proximity exposure, requiring the photomask and solar cell to maintain a micrometer-level distance. This method is technically challenging, has high production costs, and demands an extremely clean production environment. Tiny dust particles or impurities in the environment, if they fall onto the photomask or solar cell surface, can create shadows during exposure, leading to pattern defects, contamination, microcracks, or even fragmentation of the solar cells, severely impacting production yield. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing solar cells that is simpler in process, lower in cost, and has a higher production yield.
[0005] An embodiment of the present invention provides a technical solution: A method for preparing a solar cell, comprising: Obtain a yellow membrane with a metal seed layer; An insulating photoresist layer is formed on the surface of the yellow film; An ink mask layer with a grid pattern is printed on the surface of the insulating photoresist layer to obtain a battery intermediate. The battery intermediate is subjected to exposure and development processes in sequence to remove the portion of the ink mask layer and the insulating photoresist layer covered by the ink mask layer in order to form grid grooves; Metal grid lines are formed within the grid grooves and attached to the surface of the metal seed layer.
[0006] In an optional embodiment, the step of forming an insulating photoresist layer on the surface of the yellow film includes: An insulating photoresist is coated on the surface of the yellow film; The insulating photoresist is cured to form the insulating photoresist layer.
[0007] In an optional embodiment, the step of printing an ink mask layer with a gate pattern on the surface of the insulating photoresist layer includes: Ink is printed on the surface of the insulating photoresist layer using screen printing, inkjet printing, or gravure printing to obtain the ink mask layer with a grid pattern.
[0008] In an optional embodiment, the ink is a UV-curable ink or a thermosetting ink.
[0009] In an optional embodiment, the step of sequentially exposing and developing the battery intermediate to remove the portion of the ink mask layer and the insulating photoresist layer covered by the ink mask layer to form the gate groove includes: The battery intermediate is irradiated with ultraviolet light to cause cross-linking and curing of the portion of the insulating photoresist layer not covered by the ink mask layer. The uncrosslinked and uncured portions of the ink mask layer and the insulating photoresist layer are removed by a developing process to form the gate grooves.
[0010] In an optional embodiment, the step of forming metal grid lines attached to the surface of the metal seed layer within the grid line groove includes: The battery intermediate is electroplated to form the metal grid lines on the surface of the region corresponding to the grid line groove on the metal seed layer.
[0011] In an optional embodiment, after the step of forming metal grid lines attached to the surface of the metal seed layer within the grid line groove, the method further includes: Remove the remaining portion of the insulating photoresist layer and the portion of the metal seed layer not covered by the metal gate lines.
[0012] In an optional embodiment, after the step of removing the remaining portion of the insulating photoresist layer and the portion of the metal seed layer not covered by the metal gate lines, the method further includes: A metal protective layer is prepared on the metal grid line.
[0013] Compared to existing technologies, the solar cell fabrication method provided by this invention uses a negative photoresist layer formed on the surface of the yellow film. This negative photoresist is cross-linked and cured after exposure, making it less susceptible to corrosion by the developing solution during development. By printing an ink mask layer with a grid pattern on the surface of the insulating photoresist layer, light is blocked from the grid area on the insulating photoresist layer. This replaces the traditional method of using a mask for close-in exposure to complete the patterning process, effectively reducing operational difficulty and production costs. Furthermore, it avoids the high contamination risk associated with close-in exposure using a mask, significantly improving product yield. Therefore, the beneficial effects of the solar cell fabrication method provided by this invention include: simpler process, lower cost, and higher production yield. Attached Figure Description
[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as limiting the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0015] Figure 1 A flowchart illustrating a method for fabricating a solar cell according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the yellow membrane; Figure 3 This is a schematic diagram of the structure after an insulating photoresist layer is formed on the yellow film. Figure 4 This is a schematic diagram of the structure of a battery intermediate. Figure 5 This is a schematic diagram of the structure used to expose the battery intermediate using a light source; Figure 6 This is a schematic diagram of the structure of a battery intermediate after exposure treatment. Figure 7 This is a schematic diagram of the structure of a battery intermediate after development treatment. Figure 8 A schematic diagram of the structure after metal grid lines are formed in the battery intermediate; Figure 9 A schematic diagram of the structure of the battery intermediate after removing the insulating photoresist layer and the metal seed layer; Figure 10 This is a schematic diagram of the structure in which a metal protective layer is formed on a metal grid line.
[0016] Icons: 110-Silicon substrate; 120-Metal seed layer; 130-Insulating photoresist layer; 140-Ink mask layer; 150-Gate groove; 160-Electroplated pinch section; 170-Metal gate line; 180-Metal protective layer. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0018] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0019] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0020] In the description of this invention, it should be understood that the terms "upper," "lower," "inner," "outer," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this invention and to simplify the description, and are not intended to 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 invention.
[0021] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0022] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, terms such as "set" and "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0023] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
[0024] Example Please see Figure 1 , Figure 1 The diagram shown is a flowchart of a solar cell fabrication method provided in this embodiment. The solar cell fabrication method provided in this embodiment is used to fabricate solar cells and features simpler processes, lower costs, and higher production yields. Specifically, it may include: Step S101: Obtain a yellow membrane with a metal seed layer 120.
[0025] Please refer to the following: Figure 2 , Figure 2 The diagram shown is a schematic representation of the structure of the yellow membrane.
[0026] It is understood that the yellow film includes a silicon substrate 110 and two metal seed layers 120 located on opposite sides of the silicon substrate 110. Specifically, the metal seed layers 120 can be copper seed layers. The silicon substrate 110 may include a crystalline silicon layer, an amorphous silicon layer located on opposite sides of the crystalline silicon layer, and transparent conductive films located on the surfaces of the two amorphous silicon layers, respectively. The two metal seed layers 120 are located on the surfaces of the two transparent conductive films, respectively.
[0027] The crystalline silicon layer can be an N-type silicon wafer. In the actual preparation of the yellow film, the N-type silicon wafer can be texturized first. The two sides of the N-type silicon wafer can be etched with acid and alkali solutions to form a pyramid textured surface, thereby improving the surface utilization rate.
[0028] Subsequently, amorphous silicon layers are vapor-deposited on both sides of the N-type silicon wafer. One side of the amorphous silicon layer includes an intrinsic amorphous silicon layer and an N-type doped layer, while the other side of the amorphous silicon layer includes an intrinsic amorphous silicon layer and a P-type doped layer.
[0029] Subsequently, a transparent conductive film is deposited on the surface of the amorphous silicon layers on both sides to obtain a silicon substrate 110. Then, a metal seed layer 120 is grown on the transparent conductive films on both sides to prepare a yellow film.
[0030] Please continue reading. Figure 1 The method for preparing solar cells may also include: Step S102: An insulating photoresist layer 130 is formed on the surface of the yellow film.
[0031] Please refer to the following: Figure 3 , Figure 3 The diagram shows the structure after the insulating photoresist layer 130 is formed on the yellow film.
[0032] In this embodiment, an insulating photoresist is coated on the surface of the yellow film. After coating, the yellow film is placed in an oven to cure the insulating photoresist, forming an insulating photoresist layer 130 that wraps around the yellow film.
[0033] In this embodiment, the insulating photoresist is a negative photoresist, which can be exposed to undergo cross-linking and curing, and is insoluble in the developing solution after cross-linking and curing.
[0034] Please continue reading. Figure 1 The method for preparing solar cells may also include: In step S103, an ink mask layer 140 with a grid pattern is printed on the surface of the insulating photoresist layer 130 to obtain the battery intermediate.
[0035] Please refer to the following: Figure 4 , Figure 4 The diagram shown is a structural schematic of the battery intermediate.
[0036] In this embodiment, after forming an insulating photoresist layer 130 on the surface of the yellow film, an ink mask layer 140 with a grid pattern is directly printed on the surface of the insulating photoresist layer 130 by printing.
[0037] The ink mask layer 140 is opaque. During subsequent exposure processing, the portion of the insulating photoresist layer 130 covered by the ink mask layer 140 is not exposed to light and will not undergo cross-linking and curing. However, the portion of the insulating photoresist layer 130 not covered by the ink mask layer 140 is exposed and undergoes cross-linking and curing.
[0038] The printing method can be screen printing, inkjet printing, or gravure printing, etc. By printing ink on the surface of the insulating photoresist layer 130 and then curing it, an ink mask layer 140 with a grid pattern is obtained. In fact, in addition to the grid pattern, the ink mask layer 140 also has electroplated pinch pattern.
[0039] It should be noted that the ink can be UV-curable ink or thermosetting ink, which can effectively block light during the exposure process, provided it is compatible with the insulating photoresist.
[0040] Please continue reading. Figure 1 The method for preparing solar cells may also include: In step S104, the battery intermediate is subjected to exposure and development processes in sequence to remove the portion of the ink mask layer 140 and the insulating photoresist layer 130 covered by the ink mask layer 140, so as to form the grid groove 150.
[0041] Please refer to the following: Figure 5 and Figure 6 , Figure 5 The diagram shows a schematic of a structure that uses a light source to expose the battery intermediate. Figure 6 The diagram shows the structure of the battery intermediate after exposure treatment.
[0042] In step S104, ultraviolet light is used to uniformly expose the surface of the battery intermediate. The part of the insulating photoresist layer 130 covered by the ink mask layer 140 does not undergo cross-linking and curing reaction because it is not exposed to light, while the part not covered by the ink mask layer 140 undergoes cross-linking and curing when exposed to light.
[0043] Please refer to the following: Figure 7 , Figure 7 The diagram shows the structure of the battery intermediate after development treatment.
[0044] After exposure is completed, the uncrosslinked and uncured portions of the ink mask layer 140 and the insulating photoresist layer 130, i.e. the portions covered by the ink mask layer 140, are removed by a development process, thereby forming the gate groove 150 and the electroplating pinch portion 160 on the ink mask layer 140.
[0045] Please continue reading. Figure 1 The method for preparing solar cells may also include: Step S105: A metal grid line 170 is formed in the grid line groove 150, which is attached to the surface of the metal seed layer 120.
[0046] Please refer to the following: Figure 8 , Figure 8 The diagram shows the structure of the battery intermediate after the metal grid lines 170 are formed.
[0047] In step S105, the battery intermediate is placed in an electroplating solution for electroplating treatment. An electrical connection between the metal seed layer 120 and the power source is established through the electroplating clamp part 160. Electroplating is performed with the exposed part of the metal seed layer 120 in the grid groove 150 as the cathode, thereby forming metal grid lines 170 on the surface of the metal seed layer 120 corresponding to the grid groove 150.
[0048] Since the insulating photoresist layer 130 wraps around the yellow film, that is, the insulating photoresist layer covers the periphery of the yellow film, it can prevent short circuits on the NP surface during the electroplating process.
[0049] Please continue reading. Figure 1 The method for preparing solar cells may also include: Step S106: Remove the remaining portion of the insulating photoresist layer 130 and the portion of the metal seed layer 120 not covered by the metal gate line 170.
[0050] Please refer to the following: Figure 9 , Figure 9 The diagram shows the structure of the battery intermediate after the insulating photoresist layer 130 and the metal seed layer 120 have been removed.
[0051] After forming the metal gate line 170 in step S106, the remaining cross-linked and cured portion of the insulating photoresist layer 130 and the excess portion on the metal seed layer 120 are removed.
[0052] Please continue reading. Figure 1 The method for preparing solar cells may also include: Step S107: Prepare a metal protective layer 180 on the metal grid line 170.
[0053] Please refer to the following: Figure 10 , Figure 10The diagram shows a structure in which a metal protective layer 180 is formed on the metal grid line 170.
[0054] The metal protective layer 180 can be metallic tin. It can replace the elemental metal on the surface of the metal gate line 170 by tin melting and form a tin layer on the surface of the metal gate line 170 to protect the metal gate line 170 and prevent it from being oxidized.
[0055] In summary, the solar cell fabrication method provided in this embodiment achieves light shielding of the grid line area on the insulating photoresist layer 130 by printing an ink mask layer 140 with a grid line pattern on the surface of the insulating photoresist layer 130. This replaces the traditional method of using a mask for close-in exposure to complete the patterning process, effectively reducing the difficulty of operation and production costs. Furthermore, it avoids the high contamination risk associated with using a mask for close-in exposure and can significantly improve product yield.
[0056] Therefore, the solar cell fabrication method provided by this invention has the advantages of simpler process, lower cost and higher production yield.
[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for preparing a solar cell, characterized in that, include: Obtain a yellow membrane with a metal seed layer (120); An insulating photoresist layer (130) is formed on the surface of the yellow film. An ink mask layer (140) with a grid pattern is printed on the surface of the insulating photoresist layer (130) to obtain a battery intermediate; The battery intermediate is subjected to exposure and development processes in sequence to remove the portion of the ink mask layer (140) and the insulating photoresist layer (130) covered by the ink mask layer (140) to form grid grooves (150). Metal grid lines (170) are formed within the grid line groove (150) and attached to the surface of the metal seed layer (120).
2. The method for preparing a solar cell according to claim 1, characterized in that, The step of forming an insulating photoresist layer (130) on the surface of the yellow film includes: An insulating photoresist is coated on the surface of the yellow film; The insulating photoresist is cured to form the insulating photoresist layer (130).
3. The method for preparing a solar cell according to claim 1, characterized in that, The step of printing an ink mask layer (140) with a grid pattern on the surface of the insulating photoresist layer (130) includes: Ink is printed on the surface of the insulating photoresist layer (130) by means of screen printing, inkjet printing or gravure printing to obtain the ink mask layer (140) with grid pattern.
4. The method for preparing a solar cell according to claim 3, characterized in that, The ink is a UV-curable ink or a thermosetting ink.
5. The method for preparing a solar cell according to claim 1, characterized in that, The step of sequentially exposing and developing the battery intermediate to remove the portion of the ink mask layer (140) and the insulating photoresist layer (130) covered by the ink mask layer (140) to form the gate groove (150) includes: The battery intermediate is irradiated with ultraviolet light to cause cross-linking and curing of the portion of the insulating photoresist layer (130) not covered by the ink mask layer (140); The uncrosslinked and uncured portions of the ink mask layer (140) and the insulating photoresist layer (130) are removed by a developing process to form the gate groove (150).
6. The method for preparing a solar cell according to claim 1, characterized in that, The step of forming metal grid lines (170) attached to the surface of the metal seed layer (120) within the grid line groove (150) includes: The battery intermediate is electroplated to form the metal grid lines (170) on the surface of the area corresponding to the grid line groove (150) on the metal seed layer (120).
7. The method for preparing a solar cell according to claim 1, characterized in that, After the step of forming the metal grid lines (170) attached to the surface of the metal seed layer (120) within the grid line groove (150), the method further includes: Remove the remaining portion of the insulating photoresist layer (130) and the portion of the metal seed layer (120) not covered by the metal gate line (170).
8. The method for preparing a solar cell according to claim 7, characterized in that, After the step of removing the remaining portion of the insulating photoresist layer (130) and the portion of the metal seed layer (120) not covered by the metal gate line (170), the method further includes: A metal protective layer (180) is prepared on the metal grid line (170).