Conductive adhesive tape, method for removing residual electroplating adhesive and solar cell
By adding a photosensitizer to the conductive tape and then removing it using exposure and developing solutions, the problem of conductive tape residue was solved, achieving efficient electroplating and high reliability of solar cells.
Patent Information
- Application Number
- CN202410946935.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-15
- Publication Date
- 2026-01-20
AI Technical Summary
During the electroplating process of solar cells, residual conductive tape leads to a decrease in the area of the light absorption region and adhesion between cells, affecting the reliability and efficiency of the cells.
A conductive tape containing a photosensitive conductive adhesive layer is used. The photosensitive conductive adhesive layer is composed of conductive metal, photosensitizer and adhesive. The conductive tape is completely removed by exposure and developing solution treatment.
It effectively reduces the residual area of conductive tape to 0%, avoids battery cell adhesion and damage, and improves electroplating efficiency and reliability.
Smart Images
Figure CN121362528A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of solar cells, and particularly relates to a conductive adhesive tape for electroplating of a solar cell, a method for removing electroplating residual adhesive, and a solar cell. BACKGROUND
[0002] The current solar cell adopts a technical route of printing silver paste after coating, and silver grid lines are formed on the surface of an ITO conductive film after the printed silver paste is solidified. In the prior art, there is also a scheme of replacing the silver grid lines printed by silk screen printing with electroplated copper and chemically plated tin grid lines, which is achieved by first performing PVD sputtering deposition of a seed layer of copper on the ITO conductive film, using the seed layer of copper for conduction, then performing pattern transfer on the surface of the conductive layer to electroplate copper grid lines, and finally plating a layer of protective tin on the surface of the electroplated copper grid lines. This technology is an organic integration of solar cell manufacturing and metal electroplating technology.
[0003] However, after electroplating is completed, when the conductive adhesive tape is separated from the solar cell, the conductive adhesive on the conductive adhesive tape is prone to being left on the adhesive-attached position of the solar cell, so that the blue film part of the solar cell is blocked and has adhesion by the conductive adhesive, causing a decrease in the area of the light absorption region, and the solar cell is prone to adhesion between cells when being packed into a warehouse, which is difficult to be taken out individually, thereby easily causing damage to the surface of the solar cell and failure of the solar cell to be separated during stringing, so that the stringing operation cannot be completed, which seriously restricts the efficiency and reliability of the copper electroplating technical route. SUMMARY
[0004] The present application aims to at least partially solve one of the technical problems in the related art. To this end, the present application aims to provide a conductive adhesive tape for electroplating of a solar cell, a method for removing electroplating residual adhesive, and a solar cell. By adding a photosensitive agent to the photosensitive conductive adhesive layer, the photosensitive conductive adhesive layer in the exposed area can be easily separated from the solar cell, so that the conductive adhesive tape on the solar cell can be completely removed, thereby greatly reducing the residual adhesive area of the adhesion region of the solar cell, and optimally reducing to 0%, thereby avoiding the problem of cell failure of the solar cell in the adhesion mode. At the same time, the peeling of the adhesive tape caused by insufficient adhesive-attaching pressure is reduced, thereby avoiding electroplating defects. In addition, the peeling mode of the conductive adhesive tape of the present application can replace the current adhesive tape separating machine, thereby avoiding the risk of damage to the pyramid.
[0005] In one aspect of the present application, a conductive adhesive tape for electroplating of a solar cell is provided. According to an embodiment of the present application, the conductive adhesive tape comprises a photosensitive conductive adhesive layer for adhering a solar cell to be electroplated, and the photosensitive conductive adhesive layer comprises 10-20 parts by weight of a conductive metal, 10-20 parts by weight of a photosensitive agent, and 60-80 parts by weight of a binder.
[0006] According to the conductive adhesive tape for solar cell electroplating provided by the embodiments of the present application, the light-sensitive conductive adhesive layer in the exposed area can be easily separated from the solar cell by adding a photosensitive agent, so that the conductive adhesive tape on the solar cell can be completely removed, thereby greatly reducing the residual adhesive area of the bonding area of the solar cell sheet, and optimally reducing to 0%, thereby avoiding the problem of solar cell sheet failure in the bonding mode. At the same time, the electroplating failure caused by the adhesive tape falling off due to insufficient adhesive pressure is reduced. In addition, the falling-off mode of the conductive adhesive tape of the present application can replace the current adhesive tape separator, thereby avoiding the risk of damage to the pyramid.
[0007] In addition, the conductive adhesive tape for solar cell electroplating provided by the embodiments of the present application can also have the following additional technical features:
[0008] In some embodiments of the present application, the conductive metal includes at least one of nickel, copper, and silver.
[0009] In some embodiments of the present application, the photosensitive agent includes at least one of diazonium naphthoquinone, azo naphthoquinone, and azo naphthoquinone derivatives.
[0010] In some embodiments of the present application, the adhesive includes 30-50 parts by weight of a first adhesive and 20-40 parts by weight of a second adhesive, the first adhesive is a phenolic resin, and the second adhesive includes at least one of epoxy resin, urea-formaldehyde resin, triazine-formaldehyde resin, silicone resin, furan resin, unsaturated polyester, acrylic resin, polyimide, polybenzimidazole, phenolic-polyvinyl acetal, phenolic-polyamide, phenolic-epoxy resin, and epoxy-polyamide.
[0011] In some embodiments of the present application, the conductive adhesive tape further includes: a transparent insulating layer, a metal conductive layer, and an insulating coating layer which are sequentially stacked, the transparent insulating layer is arranged on a part of the surface of the metal conductive layer away from the insulating coating layer, and the remaining surface of the metal conductive layer away from the insulating coating layer is a first blank area; the insulating coating layer is arranged on a part of the surface of the metal conductive layer away from the transparent insulating layer, and the remaining surface of the metal conductive layer away from the transparent insulating layer is a second blank area, and the first blank area and the second blank area are respectively located on opposite sides of the metal conductive layer along the length direction; the light-sensitive conductive adhesive layer is arranged in the second blank area; the metal conductive layer in contact with the light-sensitive conductive adhesive layer is provided with a hole, and the hole penetrates the thickness direction of the metal conductive layer.
[0012] In some embodiments of the present application, the transparent insulating layer comprises at least one of polypropylene, polycarbonate, acrylonitrile-butadiene-styrene copolymer, phenolic resin, epoxy resin; and / or, the metal conductive layer comprises at least one of copper, silver, tin, iron, platinum; and / or, the insulating coating layer comprises at least one of polypropylene, polyethylene, polycarbonate, acrylonitrile-butadiene-styrene copolymer, polyvinyl chloride.
[0013] In some embodiments of the present application, the thickness of the photosensitive conductive adhesive layer, the transparent insulating layer and the insulating coating layer is independently 4 μm-6 μm; and / or, the thickness of the metal conductive layer is 4 μm-9 μm; and / or, the length of the photosensitive conductive adhesive layer is 1 / 4-1 / 7 of the length of the metal conductive layer; and / or, the aperture of the hole is 0.5 mm-3 mm.
[0014] In a second aspect of the present application, a method for removing the conductive adhesive tape from the solar cell after electroplating is provided. According to embodiments of the present application, the method comprises:
[0015] Exposing the area of the solar cell after electroplating to which the conductive adhesive tape is adhered to light;
[0016] Developing the exposed area with a developing solution to remove the conductive adhesive tape from the solar cell;
[0017] Cleaning the developed solar cell to remove the developing solution on the solar cell.
[0018] According to the method for removing the conductive adhesive tape from the solar cell after electroplating according to embodiments of the present application, the area of the solar cell after electroplating to which the conductive adhesive tape is adhered to is exposed to light with a light source, the photosensitive agent in the photosensitive conductive adhesive layer of the conductive adhesive tape can generate a small amount of nitrogen gas and enone under the action of light, the enone can further react with water in the developing solution to generate carboxylic acid, and the carboxylic acid can be dissolved in the developing solution, so that the photosensitive conductive adhesive layer in the exposed area can easily separate from the solar cell, thereby achieving the purpose of completely removing the conductive adhesive tape on the solar cell, greatly reducing the residual adhesive area of the adhered area of the solar cell piece, and optimally reducing to 0%, thereby avoiding the problem of solar cell piece failure in the adhered mode.
[0019] In addition, the method for removing the conductive adhesive tape from the solar cell after electroplating according to the above embodiments of the present application can further have the following additional technical features:
[0020] In some embodiments of the present application, the developing solution is a sodium carbonate solution with a concentration of 9 g / L-13 g / L.
[0021] In a third aspect, the present application provides a solar cell. According to embodiments of the present application, the solar cell is prepared by electroplating the conductive adhesive tape described in the above embodiments or removing the electroplating residue by the method described in the above embodiments. Thus, there is no conductive adhesive residue on the solar cell, avoiding the decrease of the light absorption area caused by the conductive adhesive residue, and avoiding the adhesion between the pieces, thus avoiding the damage to the surface of the solar cell piece and the failure of separating the solar cell pieces during the series welding, thus improving the preparation efficiency and reliability of the solar cell.
[0022] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS
[0023] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings, wherein:
[0024] Figure 1 Structure diagram (top view) of the solar cell piece during electroplating;
[0025] Figure 2 Structure diagram (side view) of the solar cell piece during electroplating;
[0026] Figure 3 Metallographic microscope diagram of the conductive adhesive residue at the adhesive position of the solar cell piece in the prior art;
[0027] Figure 4 SEM diagram of the conductive adhesive residue at the adhesive position of the solar cell piece in the prior art;
[0028] Figure 5 Structure diagram of the conductive adhesive tape of some embodiments of the present application;
[0029] Figure 6 Structure diagram of the metal conductive layer of some embodiments of the present application.
[0030] LIST OF REFERENCE NUMERALS
[0031] 100 - conductive adhesive tape, 101 - photosensitive conductive adhesive layer, 102 - insulating coating layer, 103 - metal conductive layer, 103-1 - hole, 104 - transparent insulating layer, 105 - first blank area, 200 - conductive clamp jaw, 300 - roller, 400 - adhesive position, 500 - electroplating tank, 1000 - solar cell piece. DETAILED DESCRIPTION
[0032] Embodiments of the present application are described below in detail with reference to examples shown in the drawings, wherein the same or similar numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.
[0033] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.
[0034] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.
[0035] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0036] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.
[0037] The present application is proposed by the inventors based on the following problems:
[0038] The preparation method of the heterojunction solar cell is as follows: first, the N-type monocrystalline silicon wafer is subjected to etching and cleaning treatment, then intrinsic amorphous silicon and N-type amorphous silicon films are deposited on the front surface of the silicon wafer, and intrinsic amorphous silicon and P-type amorphous silicon films are deposited on the back surface of the silicon wafer, then a transparent conductive film (i.e., a TCO conductive layer) is formed on the amorphous silicon, second, a copper seed layer (i.e., a PVD CU) is formed on the transparent conductive film, and finally, a copper grid line is grown as a metal electrode in an electroplating solution by taking advantage of the good conductivity of the copper seed layer. In the process of electroplating, an electroplating fixture is needed to conduct electricity to the solar cell wafer to be electroplated. As shown in Figure 1 and 2 , the electroplating fixture includes a conductive clamp 200 and a conductive adhesive tape 100, and the conductive clamp 200 and the conductive adhesive tape 100 are connected (for example, the conductive clamp 200 and the conductive adhesive tape 100 can be connected by an interaction force) to conduct electricity to the solar cell wafer 1000 to be electroplated, wherein the conductive adhesive tape 100 adheres the solar cell wafer 1000 to be electroplated by conductive adhesive. In the attached Figure 1 and 2 , 300 represents a roller for clamping the solar cell wafer and facilitating horizontal movement of the solar cell wafer. In the attached Figure 2 , 500 represents an electroplating tank for containing an electroplating solution.
[0039] However, after electroplating is completed, when the conductive adhesive tape 100 is separated from the solar cell wafer 1000, the conductive adhesive on the conductive adhesive tape 100 is easily left on the adhesive tape attachment position 400 of the solar cell wafer 1000, thereby causing the blue film part of the solar cell wafer to be blocked by the conductive adhesive and have stickiness, resulting in a decrease in the area of the light absorption region, and the solar cell wafers are easily adhered to each other when packed into a warehouse, which is difficult to separate and thus easily causes damage to the surface of the solar cell wafer and the solar cell wafers cannot be separated during stringing, which cannot complete the stringing operation, and seriously restricts the efficiency and reliability of the copper electroplating technology route.
[0040] Figure 3 The yellow area part (i.e., the black box) in the metallographic microscope image of the conductive adhesive left on the adhesive tape attachment position of the solar cell wafer, Figure 3 is the conductive adhesive left on the solar cell wafer.
[0041] The inventors found that no matter how the ratio of the adhesive and the conductive metal is optimized, due to the random size of the pyramids of the solar cell, under the condition of ensuring the adhesion of the conductive adhesive tape, the conductive adhesive is always left on the adhesive tape attachment position, as shown in the attached Figure 4 , there is a large area of conductive adhesive left in the black box area. Figure 4
[0042] In view of this, in one aspect of the present application, the present application provides a conductive tape for solar cell plating. According to the embodiments of the present application, referring to the accompanying drawings Figure 5 The conductive tape 100 includes a photosensitive conductive adhesive layer 101 for adhering the solar cell to be plated, and the photosensitive conductive adhesive layer 101 includes 10-20 parts by weight of conductive metal, 10-20 parts by weight of photosensitive agent, and 60-80 parts by weight of adhesive. Thus, by adding a photosensitive agent to the photosensitive conductive adhesive layer, the photosensitive conductive adhesive layer in the exposed area can easily be separated from the solar cell, thereby achieving the purpose of completely removing the conductive tape on the solar cell, thereby greatly reducing the residual adhesive area of the adhered area of the solar cell sheet, and optimally reducing to 0%. Thus, the problem of solar cell sheet failure in the adhered mode is avoided. At the same time, the peeling of the tape caused by insufficient taping pressure is reduced, thereby avoiding poor plating.
[0043] The principle of the conductive tape for solar cell plating according to the present application, which can achieve the above-mentioned beneficial effects, will be described in detail as follows:
[0044] The conductive tape according to the present application includes a photosensitive conductive adhesive layer, which includes conductive metal, photosensitive agent, and adhesive. The conductive metal is used to ensure that the photosensitive conductive adhesive layer is conductive, thereby enabling the conductive tape to be conductive with the solar cell to be plated. The adhesive is used to ensure that the photosensitive conductive adhesive layer has a certain adhesion, thereby enabling the conductive tape to be firmly adhered to the solar cell to be plated. The photosensitive agent can generate a small amount of nitrogen gas and enone under the action of light exposure. The enone can further react with water in the developing solution to generate carboxylic acid, which can be dissolved in the developing solution, thereby enabling the photosensitive conductive adhesive layer in the exposed area to easily separate from the solar cell. In this way, the purpose of completely removing the conductive tape on the solar cell can be achieved, thereby greatly reducing the residual adhesive area of the adhered area of the solar cell sheet, and optimally reducing to 0%. The existing conductive adhesive layer has a residual adhesive area of up to 50% after being separated from the solar cell sheet. Thus, the problem of solar cell sheet failure in the adhered mode is avoided.
[0045] At the same time, by adding a photosensitive agent to the photosensitive conductive adhesive layer, the removal degree of the conductive tape is optimized, and the taping pressure can be set larger, thereby reducing the peeling of the tape caused by insufficient taping pressure, thereby avoiding poor plating.
[0046] In addition, the peeling mode of the conductive tape according to the present application can replace the existing tape separator, thereby avoiding the risk of damage to the pyramid.
[0047] The percentage of the residual adhesive area refers to that the total area of the adhesive position of the solar cell is 100%, and the area percentage of the region where the conductive adhesive remains after the conductive adhesive tape is separated from the solar cell.
[0048] In the embodiments of the present application, the photosensitive conductive adhesive layer comprises 10-20 parts by weight of conductive metal (for example, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight of conductive metal), 10-20 parts by weight of photosensitive agent (for example, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight of photosensitive agent) and 60-80 parts by weight of adhesive (for example, 60 parts by weight, 62 parts by weight, 64 parts by weight, 66 parts by weight, 68 parts by weight, 70 parts by weight, 72 parts by weight, 74 parts by weight, 76 parts by weight, 78 parts by weight, 80 parts by weight of adhesive). By limiting the content of conductive metal, photosensitive agent and adhesive in the photosensitive conductive adhesive layer within the above range, the photosensitive conductive adhesive layer can have good conductivity, adhesion and ensure that the photosensitive conductive adhesive layer in the exposed area can easily separate from the solar cell, so as to achieve the purpose of completely removing the conductive adhesive tape on the solar cell. The inventor found that if the content of the photosensitive agent is too small, the photosensitive conductive adhesive layer in the exposed area cannot effectively separate from the solar cell, resulting in that the conductive adhesive tape on the solar cell cannot be completely removed. If the content of the photosensitive agent is too large, the cost will be too high. If the content of the conductive metal is too small, the conductivity of the photosensitive conductive adhesive layer will be poor, so that the electroplating of the solar cell cannot be effectively completed. If the content of the conductive metal is too large, the adhesion of the photosensitive conductive adhesive layer cannot be effectively ensured and the photosensitive conductive adhesive layer in the exposed area cannot effectively separate from the solar cell. If the content of the adhesive is too small, the adhesion of the photosensitive conductive adhesive layer will be poor. If the content of the adhesive is too large, the conductivity of the photosensitive conductive adhesive layer cannot be effectively ensured and the photosensitive conductive adhesive layer in the exposed area cannot effectively separate from the solar cell.
[0049] According to some specific embodiments of the present application, the photosensitive agent includes at least one of diazonium naphthoquinone, azo naphthoquinone and azo naphthoquinone derivatives. The photosensitive agent of the above type can produce a small amount of nitrogen under the action of exposure and generate enone. Enone can further react with water in the developer to generate carboxylic acid, and carboxylic acid can be dissolved in the developer, so that the photosensitive conductive adhesive layer in the exposed area can easily separate from the solar cell, so as to achieve the purpose of completely removing the conductive adhesive tape on the solar cell, thereby reducing the residual adhesive area of the adhesion area of the solar cell to 0%.
[0050] In the embodiments of the present application, the specific type of the conductive metal is not particularly limited, and can be selected by those skilled in the art according to actual needs. As some preferred solutions, the conductive metal includes at least one of nickel, copper and silver, and more preferably nickel. The metal nickel has good corrosion resistance, excellent oxidation resistance and excellent ductility, and has a relatively low cost.
[0051] In the embodiments of the present application, the specific type of the adhesive is not particularly limited, and can be selected by those skilled in the art according to actual needs. As some preferred solutions, the adhesive includes 30-50 parts by weight of a first adhesive (for example, 30 parts by weight, 32 parts by weight, 34 parts by weight, 36 parts by weight, 38 parts by weight, 40 parts by weight, 42 parts by weight, 44 parts by weight, 46 parts by weight, 48 parts by weight, 50 parts by weight of the first adhesive) and 20-40 parts by weight of a second adhesive (for example, 20 parts by weight, 22 parts by weight, 24 parts by weight, 26 parts by weight, 28 parts by weight, 30 parts by weight, 32 parts by weight, 34 parts by weight, 36 parts by weight, 38 parts by weight, 40 parts by weight of the second adhesive). The first adhesive is a phenolic resin, and the second adhesive includes at least one of an epoxy resin, a urea-formaldehyde resin, a melamine-formaldehyde resin, a silicone resin, a furan resin, an unsaturated polyester, an acrylic resin, a polyimide, a polybenzimidazole, a phenolic-polyvinyl acetal, a phenolic-polyamide, a phenolic-epoxy resin, an epoxy-polyamide. The adhesive of the above type has excellent bonding performance, further ensures that the photosensitive conductive adhesive layer is effectively bonded to the battery piece to be electroplated, and has excellent corrosion resistance and oxidation resistance. In addition, the first adhesive phenolic resin can further adapt to the photosensitive agent, which is further conducive to the photosensitive agent to play its function.
[0052] According to still some specific embodiments of the present application, referring to the accompanying drawings Figure 5 and 6The conductive adhesive tape 100 further comprises a transparent insulating layer 104, a metal conductive layer 103 and an insulating coating layer 102 which are sequentially stacked, and the transparent insulating layer 104 is arranged on a part of the surface of the metal conductive layer 103 away from the insulating coating layer 102, and the remaining surface of the metal conductive layer 103 away from the insulating coating layer 102 is a first blank area 105; the insulating coating layer 102 is arranged on a part of the surface of the metal conductive layer 103 away from the transparent insulating layer 104, and the remaining surface of the metal conductive layer 103 away from the transparent insulating layer 104 is a second blank area, and the first blank area 105 and the second blank area are respectively located on opposite sides of the metal conductive layer 103 along the length direction; the photosensitive conductive adhesive layer 101 is arranged in the second blank area; the metal conductive layer 103 in contact with the photosensitive conductive adhesive layer 101 is provided with a hole 103-1 penetrating through the thickness direction of the metal conductive layer 103. That is, the insulating layer above the photosensitive conductive adhesive layer 101 is the transparent insulating layer 104, so that light can pass through the transparent insulating layer 104, so that the photosensitive conductive adhesive layer 101 can be in an exposure condition in subsequent exposure. At the same time, the metal conductive layer 103 in contact with the photosensitive conductive adhesive layer 101 is provided with a hole 103-1, so that light can pass through the metal conductive layer 103 through the hole 103-1, so that the photosensitive conductive adhesive layer 101 can be in an exposure condition in subsequent exposure.
[0053] It should be noted that, in the accompanying drawings Figure 5 and 6 In the accompanying drawings, the X direction represents the length direction, the Y direction represents the thickness direction, and the Z direction represents the width direction.
[0054] In the embodiments of the present application, the material of the transparent insulating layer is not particularly limited, and those skilled in the art can select according to actual needs. As some preferred schemes, the transparent insulating layer comprises at least one of polypropylene, polycarbonate, acrylonitrile-butadiene-styrene copolymer, phenolic resin and epoxy resin. The insulating layer formed by the above-mentioned materials is a transparent insulating layer, so that light can pass through the transparent insulating layer. At the same time, the transparent insulating layer formed by the above-mentioned materials has a relatively high dielectric constant and excellent corrosion resistance and oxidation resistance.
[0055] In the embodiments of the present application, the material of the metal conductive layer is not particularly limited, and those skilled in the art can select according to actual needs. As some preferred schemes, the metal conductive layer comprises at least one of copper, silver, tin, iron and platinum. The metal conductive layer formed by the above-mentioned metals has good conductivity.
[0056] In the embodiments of the present application, the specific type of the insulating coating is not particularly limited, and can be selected by those skilled in the art according to actual needs. As some preferred solutions, the insulating coating comprises at least one of polypropylene, polyethylene, polycarbonate, acrylonitrile-butadiene-styrene copolymer, and polyvinyl chloride. The insulating coating formed by the above-mentioned materials has a high dielectric constant and excellent corrosion resistance and oxidation resistance.
[0057] According to still another specific embodiment of the present application, the diameter of the hole is 0.5 mm to 3 mm (for example, can be 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.). By limiting the diameter of the hole to the above range, the light can further pass through the metal conductive layer through the hole, so that the photosensitive conductive adhesive layer can be in an exposure condition during subsequent exposure.
[0058] In the embodiments of the present application, the metal conductive layer functions to conduct current. The specific size of the metal conductive layer is not particularly limited, and can be designed according to actual needs. As some specific embodiments, the thickness of the metal conductive layer is 4 μm to 9 μm, the length is 4 cm to 5 cm, and the width is 3 mm to 4 mm.
[0059] In the embodiments of the present application, the transparent insulating layer and the insulating coating function to isolate the electroplating solution and prevent the diffusion of current. It should be noted that whether the insulating coating is transparent is not particularly limited. The specific size of the transparent insulating layer and the insulating coating is not particularly limited, and can be designed according to actual needs. As some specific embodiments, the thickness of the transparent insulating layer and the insulating coating is independently 4 μm to 6 μm.
[0060] In the embodiments of the present application, the photosensitive conductive adhesive layer is a photosensitive adhesive layer with conductive properties and is easy to remove after exposure. According to still another specific embodiment of the present application, the length of the photosensitive conductive adhesive layer is 1 / 4 to 1 / 7 of the length of the metal conductive layer, thereby further ensuring that the photosensitive conductive adhesive layer functions to bond the solar cell and conduct electricity. Further, the specific size of the photosensitive conductive adhesive layer is not particularly limited, and can be designed according to actual needs. As some specific embodiments, the thickness of the photosensitive conductive adhesive layer is 4 μm to 6 μm, the length is 9 mm to 11 mm, and the width is 3 mm to 4 mm.
[0061] In the second aspect of the present application, a method for removing the conductive adhesive tape of the above embodiments from the solar cell after electroplating is provided. According to the embodiments of the present application, the method comprises the following steps:
[0062] S100: exposing the area of the solar cell after electroplating to which the conductive adhesive tape is bonded
[0063] In this step, the area of the electroplated solar cell with the conductive tape is exposed to light source, and the photosensitive agent in the photosensitive conductive adhesive layer of the conductive tape can generate a small amount of nitrogen and enone under the action of exposure, and the enone can further react with water in the developing solution to generate carboxylic acid, and the carboxylic acid can be dissolved in the developing solution, so that the photosensitive conductive adhesive layer in the exposed area can be easily separated from the solar cell, so as to achieve the purpose that the conductive tape on the solar cell is completely removed.
[0064] As a specific embodiment, multiple light sources can be provided for multi-angle exposure, so as to ensure that the photosensitive conductive adhesive layer can be completely exposed.
[0065] It should be noted that, in the process of electroplating, an electroplating hanger is needed to conduct electricity to the solar cell to be electroplated. Figure 1 As shown in the figure, the electroplating hanger includes a conductive clamp jaw and a conductive tape, and the conductive clamp jaw and the conductive tape are connected (for example, the conductive clamp jaw and the conductive tape can be connected by mutual force), which is used for conducting electricity to the solar cell to be electroplated, wherein the conductive tape is adhered to the solar cell to be electroplated through the photosensitive conductive adhesive layer.
[0066] The whole electroplating process is in a yellow light environment, so as to avoid the reaction of the photosensitive agent in the photosensitive conductive adhesive layer under the exposure condition, thereby avoiding the conductive tape from falling off the solar cell during the electroplating process.
[0067] S200: developing the exposed area with a developing solution
[0068] In this step, the exposed area is developed with a developing solution, and the enone generated by the photosensitive agent under the action of exposure can further react with water in the developing solution to generate carboxylic acid, and the carboxylic acid can be dissolved in the developing solution, so that the photosensitive conductive adhesive layer in the exposed area can be easily separated from the solar cell, that is, the conductive tape can be easily separated from the solar cell. At this time, the conductive tape and the solar cell naturally fall off, and the conductive clamp jaw can continue to clamp the conductive tape to the specified area for recycling.
[0069] According to some specific embodiments of the present application, the developing solution is a sodium carbonate solution with a concentration of 9g / L-13g / L, for example, 9g / L, 10g / L, 11g / L, 12g / L, or 13g / L, so that the developing solution can effectively make the photosensitive conductive adhesive layer in the exposed area easily separate from the solar cell.
[0070] S300: cleaning the developed solar cell
[0071] In this step, the developed solar cell can be cleaned with water to wash away the residual developing solution on the solar cell, and then dried. At this time, the electroplated solar cell without residual adhesive can be obtained.
[0072] According to the method for removing the conductive adhesive tape from the solar cell after electroplating provided in the embodiments of the present application, the area of the solar cell after electroplating with the conductive adhesive tape adhered thereon is subjected to exposure treatment by using a light source. The photosensitive agent in the photosensitive conductive adhesive layer of the conductive adhesive tape can generate a small amount of nitrogen gas and enone under the action of exposure, and the enone can further react with water in the developing solution to generate carboxylic acid, and the carboxylic acid can be dissolved in the developing solution, so that the photosensitive conductive adhesive layer in the exposed area can easily separate from the solar cell. In this way, the conductive adhesive tape on the solar cell can be completely removed, so that the residual adhesive area of the adhered area of the solar cell piece is greatly reduced, and can be optimally reduced to 0%. Thus, the problem of cell piece failure of the solar cell piece in the adhered mode is avoided.
[0073] In the third aspect of the present application, a solar cell is provided. According to the embodiments of the present application, the solar cell is prepared by electroplating the conductive adhesive tape described in the above embodiments or removing the electroplating residual adhesive by the method described in the above embodiments. Thus, there is no conductive adhesive residual on the solar cell, which avoids the decrease of the light absorption area caused by the conductive adhesive residual, and avoids the adhesion between the pieces, thereby avoiding the damage of the surface of the solar cell piece and the failure of separating the solar cell piece during the series welding, and thus the preparation efficiency and reliability of the solar cell are improved.
[0074] The embodiments of the present application are described in detail below. It should be noted that the embodiments described below are exemplary and are used to explain the present application, and should not be construed as limiting the present application. In addition, if not specifically stated, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods, and the reaction conditions not listed are also easily obtained by those skilled in the art.
[0075] Example 1
[0076] The embodiment provides a conductive adhesive tape for electroplating of a solar cell, which comprises a transparent insulating layer (the material of which is polypropylene), a metal conductive layer (copper foil) and an insulating coating layer (the material of which is polyethylene) which are sequentially stacked, and the transparent insulating layer is arranged on a part of the surface of the metal conductive layer away from the insulating coating layer, and the remaining surface of the metal conductive layer away from the insulating coating layer is a first blank area; the insulating coating layer is arranged on a part of the surface of the metal conductive layer away from the transparent insulating layer, and the remaining surface of the metal conductive layer away from the transparent insulating layer is a second blank area, and the first blank area and the second blank area are respectively located on opposite sides of the metal conductive layer along the length direction; a photosensitive conductive adhesive layer is arranged in the second blank area; a hole is arranged on the metal conductive layer in contact with the photosensitive conductive adhesive layer, and the hole penetrates the thickness direction of the metal conductive layer. The thickness of the metal conductive layer is 8 μm, the length is 4.5 cm, and the width is 3.5 mm. The thickness of the transparent insulating layer and the insulating coating layer is 5 μm, and the width is 3.5 mm. The thickness of the photosensitive conductive adhesive layer is 5 μm, the length is 10 mm, and the width is 3.5 mm.
[0077] The photosensitive conductive adhesive layer comprises 15 parts by weight of nickel powder, 15 parts by weight of a photosensitive agent diazonium naphthoquinone, 40 parts by weight of phenolic resin and 30 parts by weight of epoxy resin.
[0078] After the electroplating of the solar cell is completed, the area of the solar cell to which the conductive adhesive tape is adhered is subjected to exposure treatment by using a light source, so that the photosensitive conductive adhesive layer of the exposed area can be easily separated from the solar cell. Then, the exposed area is subjected to development by using a developing solution (11 g / L of sodium carbonate solution), and the ketone generated from the photosensitive agent under the action of exposure can further react with water in the developing solution to generate carboxylic acid, and the carboxylic acid can be dissolved in the developing solution, so that the photosensitive conductive adhesive layer of the exposed area can be easily separated from the solar cell. Finally, the developed solar cell is cleaned by using water, the residual developing solution on the solar cell is washed away, and then drying is performed.
[0079] Embodiment 2
[0080] The difference between the embodiment and embodiment 1 is only that:
[0081] The conductive adhesive tape comprises 15 parts by weight of nickel powder, 10 parts by weight of a photosensitive agent diazonium naphthoquinone, 40 parts by weight of phenolic resin and 30 parts by weight of epoxy resin.
[0082] Embodiment 3
[0083] The difference between the embodiment and embodiment 1 is only that:
[0084] The conductive adhesive tape comprises 15 parts by weight of nickel powder, 20 parts by weight of a photosensitive agent diazonium naphthoquinone, 40 parts by weight of phenolic resin and 30 parts by weight of epoxy resin.
[0085] Example 4
[0086] The difference between this example and Example 1 is only that:
[0087] The conductive adhesive tape includes 10 parts by weight of nickel powder, 15 parts by weight of a photosensitive diazonium naphthoquinone, 40 parts by weight of a phenol resin, and 30 parts by weight of an epoxy resin.
[0088] Example 5
[0089] The difference between this example and Example 1 is only that:
[0090] The conductive adhesive tape includes 20 parts by weight of nickel powder, 15 parts by weight of a photosensitive diazonium naphthoquinone, 40 parts by weight of a phenol resin, and 30 parts by weight of an epoxy resin.
[0091] Example 6
[0092] The difference between this example and Example 1 is only that:
[0093] The conductive adhesive tape includes 15 parts by weight of nickel powder, 15 parts by weight of a photosensitive diazonium naphthoquinone, 30 parts by weight of a phenol resin, and 40 parts by weight of an epoxy resin.
[0094] Example 7
[0095] The difference between this example and Example 1 is only that:
[0096] The conductive adhesive tape includes 15 parts by weight of nickel powder, 15 parts by weight of a photosensitive diazonium naphthoquinone, 50 parts by weight of a phenol resin, and 20 parts by weight of an epoxy resin.
[0097] Example 8
[0098] The difference between this example and Example 1 is only that:
[0099] The photosensitive diazonium naphthoquinone in Example 1 is replaced with an azo naphthoquinone.
[0100] Comparative Example 1
[0101] The difference between this comparative example and Example 1 is only that:
[0102] The photosensitive diazonium naphthoquinone is not added to the photosensitive conductive adhesive layer.
[0103] Comparative Example 2
[0104] The difference between this comparative example and Example 1 is only that:
[0105] The photosensitive conductive adhesive layer includes 15 parts by weight of nickel powder, 5 parts by weight of a photosensitive diazonium naphthoquinone, 40 parts by weight of a phenol resin, and 30 parts by weight of an epoxy resin.
[0106] Comparative Example 3
[0107] The difference between the present comparative example and Example 1 is only that:
[0108] The photosensitive conductive adhesive layer comprises 15 parts by weight of nickel powder, 25 parts by weight of photosensitive agent diazonium naphthoquinone, 40 parts by weight of phenolic resin and 30 parts by weight of epoxy resin.
[0109] The percentage of residual adhesive area of the adhesive position of the solar cell after exposure, development and cleaning treatment was counted, and the results are shown in Table 1. The percentage of residual adhesive area refers to that the total area of the adhesive position of the solar cell is 100%, and the area percentage of the region where the conductive adhesive remains after the conductive adhesive tape is separated from the solar cell.
[0110] Table 1
[0111] Percent Area of Residual Glue Example 1 0 Example 2 10 Example 3 0 Example 4 0 Example 5 0 Example 6 20 Example 7 0 Example 8 0 Comparative Example 1 55 Comparative Example 2 30 Comparative Example 3 0
[0112] As can be seen from Table 1, compared with Comparative Example 1, the percentage of residual adhesive area of Examples 1-8 is significantly reduced. It can be seen that after adding photosensitive agent to the photosensitive conductive adhesive layer, the photosensitive conductive adhesive layer in the exposed area can be easily separated from the solar cell, so as to achieve the purpose that the conductive adhesive tape on the solar cell is completely removed, thereby reducing the residual adhesive area of the bonding area of the solar cell.
[0113] As can be seen from Table 1, compared with Example 2, the percentage of residual adhesive area of Examples 1 and 3 can be reduced to 0%. It can be seen that when the photosensitive conductive adhesive layer contains 15-20 parts by weight of photosensitive agent, the photosensitive conductive adhesive layer in the exposed area can be further easily separated from the solar cell, so as to achieve the purpose that the conductive adhesive tape on the solar cell is completely removed, thereby reducing the residual adhesive area of the bonding area of the solar cell to 0%.
[0114] As can be seen from Table 1, compared with Example 6, the percentage of residual adhesive area of Examples 1 and 7 can be reduced to 0%. It can be seen that when the photosensitive conductive adhesive layer contains 40-50 parts by weight of the first adhesive and 20-30 parts by weight of the second adhesive, the photosensitive conductive adhesive layer in the exposed area can be further easily separated from the solar cell, so as to achieve the purpose that the conductive adhesive tape on the solar cell is completely removed, thereby reducing the residual adhesive area of the bonding area of the solar cell to 0%.
[0115] As can be seen from Table 1, compared with Example 1, the percentage of residual adhesive area of Comparative Example 2 is higher. It can be seen that if the content of photosensitive agent is too small, the photosensitive conductive adhesive layer in the exposed area cannot be effectively separated from the solar cell, resulting in that the conductive adhesive tape on the solar cell cannot be completely removed.
[0116] As can be seen from Table 1, the percentage of the residual adhesive area of Comparative Example 3 is 0% compared to Example 1, but the content of the photosensitive agent is too high, which can result in high cost.
[0117] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in the present specification and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradiction.
[0118] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.
Claims
1. An electrically conductive tape for solar cell electroplating, characterized by, The conductive adhesive layer is used for adhering the solar cell to be plated, and comprises 10-20 parts by weight of conductive metal, 10-20 parts by weight of photosensitive agent and 60-80 parts by weight of adhesive.
2. The conductive tape for electroplating of solar cells according to claim 1, wherein, The conductive metal comprises at least one of nickel, copper and silver.
3. The conductive tape for electroplating of solar cells according to claim 1, wherein The photosensitive agent comprises at least one of diazonium naphthoquinone, azo naphthoquinone and azo naphthoquinone derivative.
4. The conductive tape for electroplating of solar cells according to claim 1, wherein The adhesive comprises 30-50 parts by weight of first adhesive which is phenolic resin and 20-40 parts by weight of second adhesive which comprises at least one of epoxy resin, urea-formaldehyde resin, triazine-formaldehyde resin, silicone resin, furan resin, unsaturated polyester, acrylic resin, polyimide, polybenzimidazole, phenolic-polyvinyl acetal, phenolic-polyamide, phenolic-epoxy resin and epoxy-polyamide.
5. The conductive tape for electroplating of solar cells according to any one of claims 1 to 4, characterized in that, Further comprising: The transparent insulating layer, the metal conductive layer and the insulating coating layer are sequentially stacked, and the transparent insulating layer is arranged on a part of surface of the metal conductive layer away from the insulating coating layer, and the remaining surface of the metal conductive layer away from the insulating coating layer is a first blank area; the insulating coating layer is arranged on a part of surface of the metal conductive layer away from the transparent insulating layer, and the remaining surface of the metal conductive layer away from the transparent insulating layer is a second blank area, and the first blank area and the second blank area are respectively located on opposite sides of the metal conductive layer along the length direction; The photosensitive conductive adhesive layer is arranged in the second blank area; A hole is arranged on the metal conductive layer in contact with the photosensitive conductive adhesive layer, and the hole penetrates the thickness direction of the metal conductive layer.
6. The conductive tape for electroplating of solar cells according to claim 5, wherein The transparent insulating layer comprises at least one of polypropylene, polycarbonate, acrylonitrile-butadiene-styrene copolymer, phenolic resin and epoxy resin; And / or, the metal conductive layer comprises at least one of copper, silver, tin, iron and platinum; And / or, the insulating coating layer comprises at least one of polypropylene, polyethylene, polycarbonate, acrylonitrile-butadiene-styrene copolymer and polyvinyl chloride.
7. The conductive tape for electroplating of solar cells according to claim 5, wherein The thickness of the photosensitive conductive adhesive layer, the transparent insulating layer and the insulating coating layer is independently 4-6 μm; And / or, the thickness of the metal conductive layer is 4-9 μm; And / or, the length of the photosensitive conductive adhesive layer is 1 / 4-1 / 7 of the length of the metal conductive layer; And / or, the aperture of the hole is 0.5-3 mm.
8. A method for removing the conductive tape according to any one of claims 1 to 7 from a solar cell after electroplating, characterized by, Further comprising: Exposing the area of the solar cell on which the conductive adhesive tape is adhered after plating to light; Developing the area exposed to light by using developing solution to remove the conductive adhesive tape from the solar cell; Cleaning the developed solar cell to remove the developing solution on the solar cell.
9. The method of claim 8, wherein, The developing solution is sodium carbonate solution with concentration of 9-13 g / L.
10. A solar cell, characterized by The solar cell is prepared by plating the conductive adhesive tape according to any one of claims 1-7 or removing the plating residue by the method according to claim 8 or 9.