Solar cell vertical electroplating device and method

Abstract

The invention discloses a solar cell vertical electroplating device which comprises an electroplating process tank body, a rectifier, a spraying module, a plurality of solar cells and a plurality of anode plates, the solar cells are arranged and fixed on a carrier in a matrix mode, and a metal load is arranged on the periphery of each solar cell. The anode plates are uniformly distributed on the two insulating frames to form two anodes and are respectively arranged on two sides of the carrier, the insulating frames serve as anode shields between the adjacent anode plates, and the number of the anode plates in each anode is the same as the total number of the solar cells; the spraying assembly comprises a plurality of nozzles which are evenly distributed on the periphery of each anode plate, and outlets of the nozzles directly face one side of the carrier. According to the invention, by optimizing the electroplating device and process parameters, the preparation of the copper grid line with good thickness uniformity and line width of less than 10 microns is realized, and a rapid and effective solution is provided for further improving the photoelectric conversion efficiency of a solar cell and reducing the production and manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the field of electroplating technology, and in particular to a device and method for vertical electroplating of solar cell wafers. Background Art

[0002] Solar cells utilize the photovoltaic effect of semiconductor materials to convert light energy into electrical energy. When sunlight strikes a semiconductor material, the photon energy is absorbed by the semiconductor, causing electron transitions and the formation of electron-hole pairs. These electrons and holes are collected by metal conductive grid electrodes and, under the influence of an electric field, migrate toward the two poles, generating an electric current. Grid electrodes are often produced using a screen printing method, where a silver powder conductive paste is extruded onto the solar cell according to a pre-set pattern on a screen. The silver grid lines are then sintered at high temperatures or cured at low temperatures to form the conductive electrodes. This method is simple, easy to implement, and widely used.

[0003] However, the width of the silver electrode produced by the screen printing process is limited by the screen material and the extrusion process, and has reached its development limit. This directly leads to the inability to increase the light-collecting area of ​​the battery and the improvement of the battery's photoelectric conversion efficiency. Another core difficulty is that the conductive silver paste used in this process is expensive. As the amount used increases, the price of precious metal silver continues to rise, resulting in the inability to further reduce the production cost of solar cells. In order to reduce the production cost of solar cells and improve the photoelectric conversion efficiency of solar cells at the same time, one of the main ways to achieve this is to use a cheap metal method of micron-level patterned electroplating to produce battery metal electrodes.

[0004] Micron-scale patterning can reduce the width of the gridline electrode to a few microns. Through the copper electroplating metallization method, cheaper copper metal can be used instead of silver. The bulk resistance of copper and silver is very similar, and the electroplated copper is almost pure copper, unaffected by other fillers in the conductive silver paste. The resulting metal electrode resistance is significantly lower than that of screen-printed silver paste electrodes. Not only can the conductive gridline width be reduced to the micron level, increasing the light-collecting area, reducing the conductive gridline resistance, and minimizing electron transmission losses, thereby improving the photovoltaic conversion efficiency of solar cells, but replacing silver with inexpensive copper metal can also significantly reduce the manufacturing cost of solar cells.

[0005] Copper electroplating is widely used in a wide range of fields, including hardware, printed circuit boards, advanced packaging, and semiconductor interconnects below 0.13 microns. Developing copper electroplating processes and equipment that meet the requirements of solar cells—thin substrates to prevent breakage, high copper deposition efficiency, high equipment production capacity, and low manufacturing costs—is a hot topic in the solar cell industry.

[0006] In the prior art, the preparation method of conductive copper grid lines for solar cells is generally as follows: the solar cell substrate is placed on a carrier and fixed by clamping as an electroplating cathode. Spraying pipes are placed on both sides of the carrier, and the electroplating solution is gushed out from the opening of the spraying pipe by a circulation pump and sprayed on the surface of the solar cell substrate to realize the circulation of the solution on the side of the substrate placed vertically. The anode is placed on the side of the spraying pipe away from the solar cell substrate and is divided into a soluble titanium basket or an insoluble titanium mesh. The rectifier generates current, which is conducted to the conductive clamping point of the carrier, and the contact current is applied to the corresponding position of the electroplating cathode substrate to form a loop between the electroplating anode and the cathode. Most of the copper metal ions in the electroplating solution are produced by the dissolution of copper oxide powder. The copper metal ions are reduced to metallic copper in the patterned area on the surface of the solar cell. The copper layer thickens as the electroplating time increases, forming a conductive copper electrode grid line. However, the existing technology of electroplating copper grid electrodes is borrowed from industries such as printed circuit boards. The electroplating requirements of printed circuit boards are mainly large areas, the line width is usually more than 50 microns, the process cycle time is long, the substrate area is large (usually more than 0.5 square meters), the substrate thickness is about several millimeters, and it has good toughness and is not easily damaged.

[0007] However, the electroplating requirements of solar cells are quite different from those of printed circuit boards. For example, the area of ​​a single substrate is as small as about 0.02 square meters, the thickness of the substrate is thin, about 100 microns and easily damaged, the area to be plated is small, accounting for only about 1% of the substrate area, the grid line width is required to be within 10 microns, and the uniformity of the grid line thickness is required to be high. If the grid line thickness varies greatly, it will cause a narrow subsequent process window, directly affecting the photovoltaic conversion efficiency of the battery and the yield rate of the product. The disadvantages of the existing technical solutions are that they are not suitable for solar cells with small single-piece areas, small proportions of the plated area, narrow grid line widths, and especially high requirements for grid line thickness uniformity. The existing electroplating technology leads to poor control of the grid line morphology of the battery cell, and is unable to meet the electroplating requirements of fine line widths (within 10 microns). The grid line thickness is uneven and the body resistance is high, resulting in the subsequent etching process often causing poor grid line missing and poor electron collection, resulting in loss of photoelectric conversion efficiency. Summary of the Invention

[0008] In response to the deficiencies in the prior art, the present invention provides a device and method for vertical electroplating of solar cells, in which multiple solar cells are vertically fixed and arranged on a carrier, and multiple split anode plates are used, which correspond one to one to a single solar cell, and the size of the anode plates is adjusted in a targeted manner to achieve a uniform distribution of electric lines; at the same time, a metal load is set around each solar cell, and copper is plated on the metal load during the copper plating process of the solar cell, and the solar cell is placed at the center of the metal load, so that the electric lines around the solar cell are not concentrated and transferred to the metal load, and the electric lines are distributed by adjusting the amount of the metal load, thereby further achieving a uniform distribution of the electric lines; the spray flow and pressure of each nozzle of the spray module are individually adjustable, so that the metal ion concentration in the liquid in the tank body is uniform; the electroplating method of the present invention measures the thickness value of the copper grid electrode, calculates the uniformity value and draws a contour distribution map, adjusts the spray flow and pressure, anode shielding, metal load and other parameters in the corresponding area, and optimizes and improves the thickness uniformity of the copper grid with a line width of less than 10 microns for multiple times, thereby achieving the purpose of improving the product yield.

[0009] In order to solve the above technical problems, the present invention provides a vertical electroplating device for solar cells, comprising an electroplating process tank, a rectifier, a spray module arranged in the tank, a plurality of solar cells and a plurality of anode plates, wherein the rectifier is connected to the solar cells and the anode plates;

[0010] The solar cells are arranged vertically in a matrix and fixed on a carrier as cathodes. Metal loads fixed to the carrier are set around each solar cell. The carrier is connected to a swing mechanism for driving the carrier to move back and forth in the up and down and left and right directions.

[0011] The anode plates are evenly distributed on two insulating frames to form two anodes, and are respectively arranged on both sides of the carrier. The insulating frames serve as anode shields between adjacent anode plates. The number of anode plates in each anode is the same as the total number of solar cells.

[0012] The spray assembly includes a plurality of nozzles, which are evenly distributed around each anode plate, and the outlets of the nozzles face one side of the carrier.

[0013] The present invention arranges multiple solar cells vertically and fixedly on a carrier, uses multiple split anode plates, which correspond one-to-one to a single solar cell and are arranged on both sides of the solar cell. The size of the anode plates is specifically adjusted according to the conditions of the copper grid on the corresponding solar cell to achieve a uniform distribution of power lines.

[0014] The present invention sets a metal load around each solar cell. During the copper plating process of the solar cell, copper is also plated on the metal load. The solar cell is placed in the center of the metal load, and the power lines around the solar cell are not concentrated and transferred to the metal load. The power lines are distributed by adjusting the corresponding amount of metal load in a targeted manner, thereby further achieving uniform distribution of the power lines.

[0015] The spraying flow and pressure of each nozzle in the spray module of the present invention can be adjusted individually, so that the metal ion concentration in the liquid medicine in the tank body is uniform; it avoids the problem in the prior art that multiple nozzles are set on one pipeline, resulting in the flow and pressure of a single nozzle being unable to be regulated.

[0016] Furthermore, each of the nozzles is connected to a circulation pump via an independent pipeline with a regulating valve, so as to control the flow rate and pressure of each nozzle;

[0017] The power of the circulating pump is 1.1kW-55kW, and the flow rate is 3.2-100m 3 / h.

[0018] Furthermore, a flow equalization module is provided at the bottom of the electroplating process tank, and the flow equalization module is provided with a liquid inlet and a plurality of liquid outlets evenly distributed at the top, and each of the liquid outlets is connected to the liquid inlet through its own liquid inlet pipeline;

[0019] The cross-sectional area of ​​each liquid inlet pipe increases as the distance from the corresponding liquid outlet to the liquid inlet increases. A circulation pump is provided at the front end of the liquid inlet to pump the electroplating solution into the flow equalization module. Traditional flow equalization devices use a staggered upper and lower through-hole method, which cannot achieve true fluid uniformity. The flow equalization device of the present invention utilizes the change in pipe diameter, that is, the cross-sectional area of ​​the pipe from the liquid inlet to the distal liquid outlet is larger than that from the liquid inlet to the proximal liquid outlet. Liquid inlet pipes and liquid outlets of different pipe diameters are arranged in different regions to achieve the effect of uniform bottom flow.

[0020] Furthermore, an overflow port is provided at the upper end of the tank body, the overflow port is connected to the filter device, and the liquid outlet of the filter device is connected to each circulation pump and the circulation pump.

[0021] Furthermore, the nozzle is a Venturi nozzle, and the flow rate of the nozzle increases step by step from the bottom layer to the top layer, increasing by 1-60% at each level. In the actual electroplating process, the liquid enters the tank body from the bottom and side nozzles of the device, and overflows to the circulation pump at the top, which easily causes the metal ion concentration in the liquid at the bottom of the tank body to be higher than that at the top. This patent sets the pressure of the liquid flowing out of each nozzle to be individually adjustable, and the flow rate increases step by step from bottom to top, so that the metal ion concentration in the liquid inside the tank body is uniform.

[0022] Furthermore, the length and width of the anode sheet are 4-12% smaller than the length and width of the solar cell sheet respectively;

[0023] And / or, the distance between the anode sheet and the solar cell is 10-150 mm.

[0024] Furthermore, a heating mechanism, a cooling mechanism and a temperature sensor are provided in the electrolytic cell for regulating the temperature in the electrolytic cell to be room temperature-45°C.

[0025] A second aspect of the present invention provides a method for vertical electroplating of solar cells, using the apparatus described in the first aspect, comprising the following steps:

[0026] S1, providing electroplating solution to the tank through the spray assembly and the uniform flow module, so that the cathode and anode are immersed in the electroplating solution;

[0027] S2, turning on the rectifier, forming a circuit between the solar cell and the anode plate, and reducing the copper ions in the electroplating solution to metallic copper in the patterned area on the surface of the solar cell to form copper electrode grid lines;

[0028] S3. Measure the thickness of the copper electrode of the solar cell after electroplating, calculate the uniformity of the front and back of a single solar cell, and the uniformity of the front and back of multiple solar cells in the same carrier, and draw a contour distribution graph;

[0029] S4. adjusting one or more of the metal loading around the corresponding solar cell, the spray flow rate of the nozzle, the distance between the anode and the cathode, and the anode shielding parameters according to the contour distribution map;

[0030] S5. Repeat steps S3 and S4 until the thickness uniformity of the copper electrodes of the solar cell reaches the target value.

[0031] The electroplating method of the present invention adjusts the spray flow rate and pressure, metal load and other parameters of the corresponding area through the thickness contour distribution map of the copper grid line electrode, and optimizes and improves the thickness uniformity of the copper grid line with a line width of less than 10 microns multiple times, thereby achieving the purpose of improving product yield.

[0032] Furthermore, before S1, it also includes water washing, degreasing micro-etching and acid cleaning processes of the solar cell;

[0033] During the water washing, micro-nano bubbles are used to promote circulation; and the amount of copper seed layer removed by the degreasing micro-etching is controlled to be within 10 μm.

[0034] Furthermore, in S3, the spraying flow rate of the nozzle is adjusted by the power of the circulation pump corresponding to the nozzle.

[0035] Beneficial effects of the present invention:

[0036] By optimizing the electroplating equipment and process parameters, the present invention achieves the preparation of copper grid electrodes with good thickness uniformity and line widths below 10 microns, providing a fast and effective solution for further improving the photovoltaic conversion efficiency of solar cells and reducing production costs. Specifically:

[0037] The present invention arranges multiple solar cells vertically and fixedly on a carrier, uses multiple split anode plates, which correspond one-to-one to a single solar cell and are arranged on both sides of the solar cell. The size of the anode plates is specifically adjusted according to the conditions of the copper gate electrodes on the corresponding solar cell to achieve a uniform distribution of power lines.

[0038] The present invention sets a metal load around each solar cell. During the copper plating process of the solar cell, copper is also plated on the metal load. The solar cell is placed in the center of the metal load, and the power lines around the solar cell are not concentrated and transferred to the metal load. The power lines are distributed by adjusting the corresponding amount of metal load in a targeted manner, thereby further achieving uniform distribution of the power lines.

[0039] The spraying flow and pressure of each nozzle in the spray module of the present invention can be adjusted individually, so that the metal ion concentration in the chemical solution in the electroplating process tank is uniform; this avoids the problem in the prior art of setting multiple nozzles on a pipeline resulting in the flow and pressure of a single nozzle being unable to be regulated.

[0040] The electroplating method of the present invention measures the thickness of the copper grid electrode and draws a contour distribution map to adjust the spray flow and pressure, metal load and other parameters in the corresponding area, and optimizes multiple times to improve the thickness uniformity of the copper grid with a line width of less than 10 microns, thereby achieving the purpose of improving product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 It is a schematic structural diagram of the vertical electroplating device for solar cells of the present invention;

[0043] Figure 2 Schematic diagram of the structure of a carrier for fixing solar cells of the present invention;

[0044] Figure 3 It is a schematic diagram of the split anode structure of the present invention;

[0045] Figure 4 This is a contour distribution diagram of the copper electrode thickness before optimization of the vertical electroplating method for solar cells of the present invention;

[0046] Figure 5 This is a contour distribution diagram of the copper electrode thickness after the optimization of the vertical electroplating method for solar cells of the present invention;

[0047] Figure 6 This is a microscope image of the copper electrode after the vertical electroplating method of the solar cell is optimized according to the present invention;

[0048] Explanation of the numbers in the figure: 1. trough body, 2. solar cell, 3. anode plate, 4. carrier, 5. swing mechanism, 6. insulation frame, 7. nozzle. DETAILED DESCRIPTION

[0049] The following will provide a clear and complete description of the technical solutions of the present invention in conjunction with specific embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0050] refer to Figure 1-3 The embodiment of the present invention provides a vertical electroplating device for solar cells, comprising a tank body 1, a rectifier, a spraying module arranged in the tank body 1, a plurality of solar cells 2 and a plurality of anode plates 3, wherein the rectifier is connected to the solar cells 2 and the anode plates 3; the solar cells 2 are arranged vertically in a matrix and fixed on a carrier 4 as cathodes, and metal loads fixed on the carrier 4 are arranged around each solar cell 2, such as Figure 2 As shown, the carrier 4 is connected to a swing mechanism 5 for driving the carrier 4 to move back and forth in the up and down and left and right directions; the anode plates 3 are evenly distributed on two insulating frames 6 to form two anodes, and are respectively arranged on both sides of the carrier 4. The insulating frames 6 serve as anode shields between adjacent anode plates 3. The number of anode plates 3 in each anode is the same as the total number of solar cells 2; Figure 3 As shown, the spray assembly includes a plurality of nozzles 7 , which are evenly distributed around each anode plate 3 , and the outlets face one side of the carrier 4 .

[0051] Preferably, each of the nozzles 7 is connected to a corresponding circulation pump through a pipeline, which is used to control the flow rate and pressure of each nozzle 7; wherein the power of the circulation pump is 1.1kW-55kW, and the flow rate is 3.2-100m 3 / h, and adjust the power and flow of the circulation pump corresponding to the nozzle 7 in the corresponding area according to the thickness of the copper grid. Specifically, the nozzle 7 is a Venturi nozzle 7, and the flow of the nozzle 7 increases step by step from the lower layer to the upper layer, increasing by 1-60% at each level. In the actual electroplating process, the liquid medicine enters the tank body 1 from the bottom of the device and the side nozzle 7, and overflows to the circulation pump at the top, which easily causes the metal ion concentration in the liquid medicine at the bottom of the tank body 1 to be greater than that at the top. This patent sets the flow rate of the liquid medicine outflowing from each nozzle 7 to be individually adjustable, and the flow rate increases step by step from bottom to top, so that the metal ion concentration in the liquid medicine inside the tank body 1 is uniform.

[0052] Preferably, a flow equalization module is provided at the bottom of the tank body 1, and the flow equalization module is provided with a liquid inlet and several liquid outlets evenly distributed at the top, and each of the liquid outlets is connected to the liquid inlet through its own liquid inlet pipeline; wherein, the cross-sectional area of ​​each of the liquid inlet pipelines increases with the increase of the distance from the corresponding liquid outlet to the liquid inlet, and a circulation pump is provided at the front end of the liquid inlet for pumping electroplating solution into the flow equalization module. The flow equalization device of this embodiment utilizes the change of pipe diameter, that is, the cross-sectional area of ​​the pipe from the liquid inlet to the distal liquid outlet is larger than that from the liquid inlet to the proximal liquid outlet, and liquid inlet pipes and liquid outlets of different pipe diameters are arranged in different regions to achieve the effect of uniform flow at the bottom.

[0053] Preferably, an overflow port is provided at the upper end of the tank body 1, the overflow port is connected to the filtering device, and the liquid outlet of the filtering device is connected to each circulation pump and the circulation pump.

[0054] Preferably, the length and width of the anode sheet are respectively 4-12% smaller than the length and width of the solar cell 2; and the distance between the anode sheet and the solar cell is 10-150 mm.

[0055] Preferably, a heating mechanism, a cooling mechanism and a temperature sensor are further provided in the electrolytic cell for regulating the temperature in the electrolytic cell to be room temperature-45°C.

[0056] Another embodiment provides a method for vertical electroplating of solar cells, using the apparatus described in the above embodiment, including the following steps:

[0057] S1, providing electroplating solution to the tank 1 through the spray assembly and the uniform flow module, so that the cathode and anode are immersed in the electroplating solution;

[0058] S2, turn on the rectifier, a circuit is formed between the solar cell 2 and the anode plate 3, and the copper ions in the electroplating solution are reduced to metallic copper in the patterned area on the surface of the solar cell 2 to form copper electrode grid lines;

[0059] S3, measuring the thickness of the copper electrode of the solar cell 2 after electroplating, calculating the uniformity of the front and back surfaces of a single solar cell 2 and the uniformity of the front and back surfaces of multiple solar cells 2 in the same carrier 4, and drawing a contour distribution graph;

[0060] S4, adjusting one or more of the metal load around the corresponding solar cell 2, the spray flow rate of the nozzle 7, the distance between the anode and the cathode, and the anode shielding parameter according to the contour distribution map;

[0061] S5, repeat steps S3 and S4 until the thickness uniformity of the copper electrode of the solar cell 2 reaches the target value. The thickness distribution contour lines of the copper grid of the solar cell 2 before and after optimization are as follows: Figure 4 and Figure 5 As shown in FIG, the range uniformity before optimization is 31.7%, and the range uniformity after optimization is 6.3%. The thickness uniformity of the optimized copper grid is significantly improved. In addition, the solar cell micrograph of the electroplated copper grid of this embodiment is shown in FIG. Figure 6 As shown, the copper gate has a line width of 9 μm, a uniform thickness, and a clear boundary. It can be seen that the method of the present invention can realize the preparation of a copper gate with a line width of less than 10 μm.

[0062] Preferably, prior to S1, the solar cell 2 is further subjected to water washing, degreasing micro-etching, and pickling. During the water washing, micro-nano bubbles are used to promote circulation, and the removal of the copper seed layer by the degreasing micro-etching is controlled to be within 10 μm. In S3, the spray flow rate of the nozzle 7 is adjusted by the power of the corresponding circulation pump of the nozzle 7.

[0063] In summary, the present invention optimizes the electroplating device and process parameters to achieve the preparation of copper grid lines with good thickness uniformity and line width below 10 microns, providing a fast and effective solution for further improving the photoelectric conversion efficiency of solar cells and reducing production costs. The present invention arranges multiple solar cells vertically and fixedly on a carrier, adopts multiple split anode plates, which correspond one to one to a single solar cell and are arranged on both sides of the solar cell, and the size of the anode plates is adjusted according to the situation of the copper grid on the corresponding solar cell to achieve the effect of uniform distribution of electric lines; a metal load is set around each solar cell, and copper is plated on the metal load at the same time during the copper plating process of the solar cell, and the solar cell is placed at the center of the metal load, so that the electric lines around the solar cell are not concentrated and transferred to the metal load, and the amount of the corresponding metal load is adjusted to distribute the electric lines, thereby further achieving uniform distribution of the electric lines; the spray flow and pressure of each nozzle in the spray module are individually adjustable, so that the metal ion concentration in the liquid in the tank body is uniform; the problem of multiple nozzles being set on a pipeline in the prior art that the flow and pressure of a single nozzle cannot be regulated is avoided; the electroplating method of the present invention adjusts the spray flow and pressure, metal load and other parameters of the corresponding area through the thickness contour distribution map of the copper grid electrode, and optimizes and improves the thickness uniformity of the copper grid line with a line width of less than 10 microns for multiple times, thereby achieving the purpose of improving the product yield.

[0064] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A vertical electroplating device for solar cells, characterized in that: It includes an electroplating process tank, a rectifier, and a spray module, a plurality of solar cells and a plurality of anode plates arranged in the tank, wherein the rectifier is connected to the solar cells and the anode plates; The solar cells are arranged vertically in a matrix and fixed on a carrier as cathodes. Metal loads fixed on the carrier are arranged around each solar cell. The carrier is connected to a swing mechanism to drive the carrier to move back and forth in the up and down and left and right directions. The anode plates are evenly distributed on two insulating frames to form two anodes, and are respectively arranged on both sides of the carrier. The insulating frames serve as anode shields between adjacent anode plates. The number of anode plates in each anode is the same as the total number of solar cells. The spray assembly includes a plurality of nozzles, which are evenly distributed around each of the anode plates, and the outlets of the nozzles face one side of the carrier.

2. The vertical electroplating device for solar cells according to claim 1, characterized in that: Each of the nozzles is connected to a circulation pump through an independent pipeline, and the circulation pump is controlled by a frequency converter to control the liquid supply pressure and flow rate. Each pipeline is equipped with a regulating valve to control the spraying flow rate of each nozzle. The power of the circulating pump is 1.1kW-55kW, and the flow rate is 3.2-100m 3 / h.

3. The vertical electroplating device for solar cells according to claim 2, characterized in that: A flow-uniform module is provided at the bottom of the electroplating process tank, and the flow-uniform module is provided with a liquid inlet and a plurality of liquid outlets evenly distributed at the top, and each of the liquid outlets is connected to the liquid inlet through a respective liquid inlet pipeline; The cross-sectional area of ​​each liquid inlet pipeline increases with the distance from the corresponding liquid outlet to the liquid inlet, so that the pressure of each liquid outlet remains consistent. A circulating pump is arranged at the front end of the liquid inlet to pump electroplating solution into the flow-uniform module.

4. The vertical electroplating device for solar cells according to claim 3, characterized in that: An overflow port is arranged at the upper end of the electroplating process tank body, and the overflow port is connected to the filtering device. The filtering device uses a filter element smaller than 5um to ensure that particles larger than half of the 10um grid line width, i.e. 5um, are removed through the filter element to ensure the cleanliness of the electroplating solution. The liquid outlet of the filtering device is connected to each circulation pump.

5. The vertical electroplating device for solar cells according to claim 2, characterized in that: The nozzle is a Venturi nozzle, and the flow rate of the nozzle increases step by step from the lower layer to the upper layer, with each stage increasing by 1-60%.

6. The vertical electroplating device for solar cells according to claim 1, characterized in that: The length and width of the anode sheet are respectively 4-12% smaller than the length and width of the solar cell sheet; And / or, the distance between the anode sheet and the solar cell is 10-150 mm.

7. The vertical electroplating device for solar cells according to claim 1, characterized in that: The electroplating process tank is also provided with a heating mechanism, a cooling mechanism and a temperature sensor for adjusting the temperature in the electroplating process tank to room temperature-45°C.

8. A method for vertical electroplating of a solar cell, characterized in that: The device according to any one of claims 1 to 7 comprises the following steps: S1, providing electroplating solution to the electroplating process tank through the side spraying assembly and the bottom uniform flow module, so that the cathode and the anode are immersed in the electroplating solution; S2, turn on the rectifier, the solar cell conducts electricity through the carrier and forms a loop between the anode plate, and the copper ions in the electroplating solution are reduced to metallic copper in the pattern area on the surface of the solar cell to form a copper grid electrode; S3, measuring the thickness of the copper electrode of the solar cell after electroplating, calculating the uniformity of the front and back of a single solar cell and the uniformity of the front and back of multiple solar cells in the same carrier, and drawing a contour distribution graph; S4, adjusting one or more of the metal load around the corresponding solar cell, the spray flow rate of the nozzle, the distance between the anode and the cathode, and the anode shielding parameters according to the contour distribution map; S5. Repeat steps S3 and S4 until the thickness uniformity of the copper electrode of the solar cell reaches the target value.

9. The method for vertical electroplating of a solar cell according to claim 1, characterized in that: Before S1, it also includes water washing, degreasing micro-etching and pickling processes for solar cells; Wherein, during the water washing, the circulation is promoted by micro-nano bubbles; and the removal amount of the copper seed layer by the degreasing micro-etching is controlled within 10 um.

10. The vertical electroplating method for solar cell according to claim 1, characterized in that: In S3, the spraying flow rate and pressure of the nozzle are adjusted through a regulating valve on the pipeline where the nozzle is located, as well as the power and frequency of the corresponding circulation pump.

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