TOPCon battery metallization method

Abstract

The invention provides a TOPCon battery metallization method, and relates to the technical field of solar cells, and the method comprises the following steps: providing a blue diaphragm; preparing a metal seed layer on one side of the blue membrane and then drying; preparing a metal seed layer on the other side of the blue diaphragm, and then drying or sintering; preparing main and auxiliary grids on the metal seed layer on one side and then drying, wherein the main and auxiliary grids are made of non-silver paste; and preparing main and auxiliary grids on the metal seed layer on the other side, and sintering to complete metallization of the battery piece. In the invention, the main grid and the auxiliary grid are made of the non-silver paste, and the non-silver paste is used for replacing traditional silver paste, so that the use amount of silver is greatly reduced, the cost of raw materials is reduced, the production cost of the TOPCon battery is reduced, the dependence on noble metal resources is relieved when the TOPCon battery is produced, and the requirement of sustainable development is better met.

Description

Technical Field

[0001] The invention relates to the technical field of solar cell batteries, and in particular to a TOPCon battery metallization method. Background Art

[0002] TOPCon cells are tunnel oxide passivated contact solar cells with N-type silicon as substrate.

[0003] The traditional metallization process of TOPCon batteries is to use silver paste screen printing, drying, and then high-temperature sintering.

[0004] For example, a Chinese patent with authorization announcement number CN118198207B discloses a method for preparing a TOPCon battery based on poly stacking optimization, including S1, preparing a first tunneling oxide layer; S2, preparing a first amorphous silicon layer on the first tunneling oxide layer; S3, preparing a second tunneling oxide layer on the first amorphous silicon layer; S4, preparing a second amorphous silicon layer on the second tunneling oxide layer; S5, preparing a third amorphous silicon layer on the second amorphous silicon layer; S6, preparing a Mask protective layer on the third amorphous silicon layer; S7, high temperature annealing and removing the Mask protective layer; S8, preparing a silicon nitride anti-reflection layer on the third amorphous silicon layer; S9, printing silver paste on the silicon nitride anti-reflection layer; when the TOPCon battery is manufactured by this method, the second tunneling oxide layer, the second amorphous silicon layer and the third amorphous silicon layer do not need to be removed. At the same time, the method adopts a comprehensive tunneling and amorphous silicon method, which achieves 100% compatibility with production line equipment, without the need to add any new equipment, reducing costs while also improving efficiency.

[0005] However, the silver content in traditional silver paste is relatively high. Using a large amount of silver paste will consume a large amount of precious metal resources, resulting in a higher production cost of the silver paste, thereby increasing the production cost of TOPCon solar cells. Summary of the invention

[0006] The invention provides a TOPCon battery metallization method, which is used to solve the technical problem of high cost when silver paste screen printing is currently adopted.

[0007] In order to solve the above technical problems, the present invention discloses a TOPCon battery metallization method, comprising the following steps:

[0008] Step 1: Provide a blue film;

[0009] Step 2: Prepare a metal seed layer on one side of the blue film and then dry it;

[0010] Step 3: Prepare a metal seed layer on the other side of the blue film and then dry or sinter it;

[0011] Step 4: preparing the main and auxiliary gates on one side of the metal seed layer and then drying them. The main and auxiliary gates are made of non-silver paste;

[0012] Step 5: Prepare the main and auxiliary grids on the other side of the metal seed layer and then sinter them to complete the metallization of the cell.

[0013] Preferably, the blue film comprises:

[0014] A semiconductor substrate, wherein a tunneling layer is disposed on a first surface of the semiconductor substrate;

[0015] A first conductivity type semiconductor region on the tunneling layer contains impurities of the first conductivity type;

[0016] Impurities of a second conductivity type opposite to the first conductivity type are located on the second surface of the semiconductor substrate to form a second conductivity type semiconductor region opposite to the first conductivity type semiconductor region;

[0017] a first passivation film on the first conductivity type semiconductor region;

[0018] A first electrode formed on the first passivation film and connected to the first conductivity type semiconductor region through an opening formed in the first passivation film;

[0019] A second passivation film A on the second conductivity type semiconductor region;

[0020] A second passivation film B on the second passivation film A;

[0021] A second electrode formed on the second passivation film B and connected to the second conductivity type semiconductor region through openings formed in the second passivation film B and the second passivation film A;

[0022] An isolation portion for preventing a first conductive type semiconductor region from contacting a second conductive type semiconductor region, wherein the isolation portion does not include a tunneling layer and the first conductive type semiconductor region, and is located at an edge portion of a first surface of a semiconductor substrate, and a first passivation film covers the first surface of the semiconductor substrate and the isolation portion.

[0023] Preferably, in step 2 and step 3, the metal seed layer includes but is not limited to a silver seed layer, a nickel seed layer, a silver-coated copper seed layer, and a silver-coated nickel seed layer.

[0024] Preferably, in step 4, the non-silver paste includes one or more of silver-coated copper paste, silver-coated aluminum paste, silver-coated nickel paste, and pure copper paste.

[0025] Preferably, in step 2 and step 3, the metal seed layer has a thickness of 0.05-5 μm and a width of 3-60 μm.

[0026] Preferably, the gate line layer of the metal seed layer is a single layer or multiple layers, the sintering temperature of the silver seed layer is 600-850°C, the sintering temperature of the nickel seed layer is 300-700°C, and the sintering temperature of the silver-coated copper seed layer and the silver-coated nickel seed layer is 400-850°C.

[0027] Preferably, the gate line layer of the main and auxiliary gates is a single layer or multiple layers.

[0028] Preferably, the main and auxiliary grids are prepared by any one of printing, electroplating, sputtering, spraying, coating, rolling and roll printing.

[0029] Preferably, in step 5, the battery cell is subjected to low temperature sintering, and the sintering temperature is 200-600°C.

[0030] Preferably, in step 5, the battery cell is sintered at a high temperature of 600-850°C.

[0031] The technical solution of the present invention has the following advantages: The present invention provides a TOPCon cell metallization method, which relates to the technical field of solar cells, and includes the following steps: providing a blue film; preparing a metal seed layer on one side of the blue film and drying it; preparing a metal seed layer on the other side of the blue film and drying or sintering it; preparing a main and auxiliary grid on one side of the metal seed layer and drying it, and the main and auxiliary grid are made of non-silver paste slurry; preparing a main and auxiliary grid on the other side of the metal seed layer and sintering it to complete the cell metallization. In the present invention, the main and auxiliary grids are made of non-silver paste slurry, and the non-silver paste slurry replaces the traditional silver paste, which greatly reduces the use of silver, thereby reducing the cost of raw materials and the production cost of TOPCon cells. When producing TOPCon cells, the dependence on precious metal resources is alleviated, which is more in line with the requirements of sustainable development.

[0032] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the devices particularly pointed out in the written description and the drawings of the description.

[0033] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 A schematic diagram of a TOPCon battery metallization method according to the present invention;

[0036] Figure 2 This is a schematic diagram of the blue diaphragm structure in the present invention;

[0037] Figure 3 It is a schematic diagram of the structure of the screen printing equipment in the present invention;

[0038] Figure 4 It is a side view of the spraying assembly of the present invention;

[0039] Figure 5 This is a front view of the scraper in the present invention;

[0040] Figure 6 For the present invention Figure 3 A magnified view of the structure in the middle.

[0041] In the figure: 1, frame; 2, printing platform; 3, crossbeam; 4, linear module; 5, slide; 6, slurry transfer box; 7, spray assembly; 8, limit frame; 9, blue film; 901, semiconductor substrate; 902, tunneling layer; 903, first conductive type semiconductor region; 904, second conductive type semiconductor region; 905, first passivation film; 906, first electrode; 907, second passivation film A; 908, second passivation film B; 10, cross plate; 11, second electric push rod; 12, telescopic spring; 13, scraper; 14 , collecting hole; 15, conveying pipe; 16, fixed plate; 17, vertical sliding groove; 18, first spring; 19, movable plate; 20, first magnetic block; 21, mounting plate; 22, pressure roller; 23, second magnetic block; 24, first electric push rod; 25, horizontal sliding groove; 26, longitudinal sliding groove; 27, gear column; 28, first rack; 29, sliding rod; 30, connecting rod; 31, reset spring; 32, limit plate; 33, second rack; 34, connecting spring; 35, support; 36, reciprocating screw; 37, driving motor; 38, scraper. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0043] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes, and do not specifically refer to the order or sequence, nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions and technical features between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0044] The embodiment of the present invention provides a TOPCon battery metallization method, such as Figure 1 As shown, the following steps are included:

[0045] Step 1: providing a blue film 9;

[0046] Step 2: preparing a metal seed layer on one side of the blue film 9 and then drying it;

[0047] Step 3: preparing a metal seed layer on the other side of the blue film 9 and then drying or sintering it;

[0048] Step 4: preparing the main and auxiliary gates on one side of the metal seed layer and then drying them. The main and auxiliary gates are made of non-silver paste;

[0049] Step 5: Prepare the main and auxiliary grids on the other side of the metal seed layer and then sinter them to complete the metallization of the cell;

[0050] In step 2 and step 3, the metal seed layer includes but is not limited to a silver seed layer, a nickel seed layer, a silver-coated copper seed layer, and a silver-coated nickel seed layer;

[0051] In step 4, the non-silver paste includes but is not limited to one or more of silver-coated copper paste, silver-coated aluminum paste, silver-coated nickel paste, and pure copper paste;

[0052] In step 2 and step 3, the metal seed layer has a thickness of 0.05-5 μm and a width of 3-60 μm, the gate line layer is a single layer or multiple layers, the sintering temperature of the silver seed layer is 600-850° C., the sintering temperature of the nickel seed layer is 300-700° C., and the sintering temperature of the silver-coated copper seed layer and the silver-coated nickel seed layer is 400-850° C.;

[0053] The gate line layer of the main and auxiliary gates is single-layer or multi-layer;

[0054] The main and auxiliary grids are prepared by any one of the processes of printing, electroplating, sputtering, spraying, coating, rolling and roll printing.

[0055] The working principle and beneficial effects of the above technical solution are as follows: first prepare a blue diaphragm 9, which undergoes the existing TOPCon process in sequence, then prepare a metal seed layer on one side of the blue diaphragm 9 and dry it, prepare a metal seed layer on the other side of the blue diaphragm 9 and dry it or sinter it, the metal seed layer includes but is not limited to a silver seed layer, a nickel seed layer, a silver-coated copper seed layer, and a silver-coated nickel seed layer, then prepare a main and auxiliary grid on one side of the metal seed layer and dry it, prepare a main and auxiliary grid on the other side of the metal seed layer and sinter it, complete the metallization of the battery cell, the main and auxiliary grid are made of non-silver paste, and the non-silver paste includes but is not limited to one or more of silver-coated copper paste, silver-coated aluminum paste, silver-coated nickel paste, and pure copper paste. In the present invention, the main and auxiliary grids are made of non-silver paste, and the non-silver paste replaces the traditional silver paste, which greatly reduces the use of silver, thereby reducing the cost of raw materials and the production cost of TOPCon batteries. When producing TOPCon batteries, the dependence on precious metal resources is alleviated, which is more in line with the requirements of sustainable development.

[0056] like Figure 2 As shown, the blue diaphragm 9 includes:

[0057] A semiconductor substrate 901, a tunneling layer 902 is disposed on a first surface of the semiconductor substrate 901;

[0058] The first conductivity type semiconductor region 903 on the tunneling layer 902 contains impurities of the first conductivity type;

[0059] Impurities of a second conductivity type opposite to the first conductivity type are located on the second surface of the semiconductor substrate 901 to form a second conductivity type semiconductor region 904 opposite to the first conductivity type semiconductor region 903;

[0060] A first passivation film 905 on the first conductivity type semiconductor region 903;

[0061] A first electrode 906 formed on the first passivation film 905 and connected to the first conductivity type semiconductor region 903 through an opening formed in the first passivation film 905;

[0062] A second passivation film A907 on the second conductivity type semiconductor region 904;

[0063] A second passivation film B908 on the second passivation film A907;

[0064] A second electrode formed on the second passivation film B908 and connected to the second conductivity type semiconductor region 904 through openings formed in the second passivation film B908 and the second passivation film A907;

[0065] An isolation portion is used to prevent the first conductive type semiconductor region 903 from contacting the second conductive type semiconductor region 904, wherein the isolation portion does not include the tunneling layer 902 and the first conductive type semiconductor region 903, and is located at the edge portion of the first surface of the semiconductor substrate 901, and the first passivation film 905 covers the first surface of the semiconductor substrate 901 and the isolation portion.

[0066] Specific:

[0067] Embodiment 1 provides a TOPCon battery metallization method, comprising the following steps: first providing a blue film 9, which undergoes the existing TOPCon process flow in sequence, printing a silver seed layer on the blue film 9, and performing high-temperature sintering at a sintering temperature of 600-850°C, then printing a silver-coated copper slurry to prepare a main grid and a secondary grid, thereby obtaining a battery cell, then low-temperature sintering the battery cell at a low-temperature sintering temperature of 200-600°C, and finally completing the battery cell metallization through a LECO process. In this embodiment, silver-coated copper paste is used instead of traditional silver paste. The silver-coated copper paste has copper as the core and a silver layer wrapped on the outside. Under the premise of ensuring performance, the amount of silver used is greatly reduced, thereby reducing the cost of raw materials and significantly reducing the cost of battery manufacturing. The conductivity of the silver-coated copper paste is lower than that of the silver paste, so a silver seed layer is set, and the conductivity can be effectively improved by the silver seed layer; the LECO process is a laser enhanced contact optimization process, which is a technology that uses high-intensity lasers to irradiate battery cells and apply a deflection voltage at the same time. The process significantly reduces the contact resistance between metals and semiconductors through the local current generated by laser irradiation, thereby optimizing the electrical performance of the battery.

[0068] Embodiment 2 provides a TOPCon cell metallization method, comprising the following steps: first providing a blue film 9, the blue film 9 undergoes the existing TOPCon process flow in sequence, printing a silver seed layer on the blue film 9, then printing a silver-coated copper paste to prepare a main and a secondary grid, thereby preparing a cell, then sintering the cell at a high temperature of 600-850°C, and finally completing the cell metallization through a LECO process. Compared with Embodiment 1, the above method can reduce the sintering steps and reduce the cost of sintering equipment.

[0069] Example 3 provides a TOPCon battery metallization method, including the following steps: first providing a blue film 9, the blue film 9 undergoes the existing TOPCon process flow in sequence, printing a silver seed layer on the blue film 9, and then printing a silver-coated copper slurry to prepare a main and auxiliary grid, thereby making a battery cell, and then sintering the battery cell at a low temperature, the sintering temperature is 200-600°C, and finally completing the battery cell metallization through a LECO process.

[0070] Embodiment 4 provides a TOPCon battery metallization method, comprising the following steps: first providing a blue film 9, the blue film 9 undergoes the existing TOPCon process flow in sequence, laser grooving on the blue film 9, then printing a nickel seed layer, the sintering temperature of the nickel seed layer is 300-500°C, then printing a silver-coated copper paste to prepare a main and a secondary grid, thereby preparing a battery cell, and then sintering the battery cell at a low temperature to complete the battery cell metallization. Compared with Embodiment 1, Embodiment 2, and Embodiment 3, the above scheme uses a nickel seed layer, the nickel sintering temperature is low, and it can be co-fired with the silver-coated copper paste, thereby producing lower thermal damage to the battery material. By replacing the silver seed layer with a nickel seed layer, the preparation cost can be reduced. The oxidation resistance of nickel is better than that of silver, and the corrosion resistance of nickel is better than that of silver, which can improve the reliability of the nickel seed layer. The use of low-temperature sintering can reduce energy consumption and further reduce the metallization cost; due to the difference in radius and lattice constant, the silver-silicon lattice mismatch is large, and the nickel-silicon alloy can increase the contact area.

[0071] Embodiment 5 provides a TOPCon battery metallization method, comprising the following steps: first providing a blue film 9, the blue film 9 undergoes the existing TOPCon process flow in sequence, laser grooving the blue film 9, then printing a nickel seed layer, and then printing a pure copper slurry to prepare a main and a secondary grid, thereby preparing a battery cell, and then sintering the battery cell at a low temperature to complete the battery cell metallization. Compared with embodiment 4, the above embodiment uses pure copper slurry instead of silver-coated copper slurry, further reducing the amount of silver used, thereby significantly reducing the preparation cost.

[0072] In one embodiment, the main and auxiliary grids are printed using a screen printing device;

[0073] like Figure 3 , Figure 4 As shown, the screen printing device includes a frame 1, a printing platform 2 is arranged on the frame 1, a crossbeam 3 is arranged above the printing platform 2, both ends of the crossbeam 3 are connected to the frame 1 through supporting columns, a linear module 4 is arranged on the crossbeam 3, a slide 5 is slidably arranged on the linear module 4, a slurry transfer box 6 is arranged at the lower end of the slide 5, and a spray assembly 7 is arranged below the slurry transfer box 6;

[0074] A limit frame 8 is arranged above the printing platform 2, and a blue film 9 is placed in the limit frame 8;

[0075] A slurry smearing assembly is arranged on the rear side of the slurry transfer box 6, and the slurry smearing assembly includes a transverse plate 10, one end of which is connected to the rear side wall of the slurry transfer box 6, a second electric push rod 11 is slidably arranged on the lower surface of the transverse plate 10, and the side wall of the second electric push rod 11 is connected to the rear side wall of the slurry transfer box 6 through a telescopic spring 12, and a scraper 13 is arranged at the lower end of the second electric push rod 11.

[0076] The working principle and beneficial effects of the above technical solution are as follows: when printing the main and auxiliary grids, the blue film sheet 9 is placed in the limiting frame 8 on the printing platform 2, and the limiting frame 8 can limit the blue film sheet 9 around to prevent the blue film sheet 9 from moving during the screen printing process, and then the screen is set on the blue film sheet 9, the linear module 4 and the spray assembly 7 are started, the linear module 4 drives the slide 5 to move, thereby driving the slurry transfer box 6 and the spray assembly 7 to move, the slurry transfer box 6 stores non-silver slurry, the spray assembly 7 can spray the non-silver slurry onto the surface of the screen, and the slide 5 drives the spray assembly 7 to move. Component 7 moves along the length direction of the blue diaphragm 9, so as to evenly spray the non-silver paste slurry. The second electric push rod 11 extends downward to drive the scraper 13 to move downward. The extension length of the second electric push rod 11 is adjusted according to the preset thickness of the non-silver paste slurry, so that the distance between the scraper 13 and the surface of the screen is equal to the preset thickness of the non-silver paste slurry. Then, during the movement of the slurry coating component with the slurry transfer box 6, the scraper 13 contacts the non-silver paste slurry sprayed on the surface of the screen, and then scrapes the non-silver paste slurry flat, so that the non-silver paste slurry is evenly spread on the surface of the screen to complete the printing of the main and sub-grids.

[0077] In one embodiment, Figure 4 , Figure 5 As shown, the scraper 13 is in the shape of a right-angled trapezoid. An inclined surface is provided on the side of the scraper 13 close to the slurry transfer box 6. A cavity is provided inside the scraper 13. A plurality of collecting holes 14 are provided on the inclined surface of the scraper 13. The collecting holes 14 are connected to the inside of the cavity.

[0078] The working principle and beneficial effects of the above technical solution are as follows: during the scraping process of the scraper 13, excess non-silver paste slurry is scraped onto the inclined surface of the scraper 13, and then enters the cavity inside the scraper 13 through the collecting hole 14, thereby collecting the excess non-silver paste slurry, reducing the waste of non-silver paste slurry, and saving preparation costs.

[0079] In one embodiment, Figure 5 As shown, supports 35 are symmetrically arranged on the left and right sides of the scraper 13, and a reciprocating screw rod 36 is rotatably arranged between the supports 35. One end of the reciprocating screw rod 36 extends to the outside of the support 35 and is connected to the output end of the driving motor 37. A scraper plate 38 is slidably arranged on the inclined surface of the scraper 13, and the scraper plate 38 slides along the length direction of the inclined surface. A threaded hole is arranged in the scraper plate 38, and the scraper plate 38 is transmission-connected to the reciprocating screw rod 36 through the threaded hole.

[0080] The working principle and beneficial effects of the above technical solution are as follows: the two ends of the scraper 13 are slidably connected to the inner wall of the limiting frame 8, so that during the scraping process of the scraper 13, the end of the scraper 13 contacts the inner wall of the limiting frame 8, and the non-silver paste slurry adhering to the limiting frame 8 can be scraped off, thereby improving the collection effect of the non-silver paste slurry. When the scraper 13 contacts the inner wall of one end of the limiting frame 8, the excess non-silver paste slurry is between the inner wall of the limiting frame 8 and the inclined surface of the scraper 13, and then the drive motor 37 is started, and the drive motor 37 drives the non-silver paste slurry to the limit frame 8. The multifilament rod 36 rotates between the supports 35, thereby driving the scraper 38 to slide back and forth along the inclined surface. During the sliding process of the scraper 38, the non-silver paste slurry can be scraped to the collecting hole 14, so that the non-silver paste slurry flows into the cavity through the collecting hole 14, completing the collection of the non-silver paste slurry, reducing the waste of non-silver paste slurry, saving costs, and the scraper 38 can clean the inclined surface of the scraper 13, reducing the residue of non-silver paste slurry, eliminating the need for manual cleaning, and improving the degree of automation of the slurry coating component.

[0081] In one embodiment, Figure 4 As shown, a slurry transfer pump is arranged outside the slurry transfer box 6, the output end of the slurry transfer pump is connected with the inside of the slurry transfer box 6, the input end of the slurry transfer pump is connected with one end of the delivery pipe 15, and the other end of the delivery pipe 15 is connected with the inside of the cavity;

[0082] The delivery pipe 15 adopts a telescopic pipe.

[0083] The working principle and beneficial effects of the above technical solution are as follows: the non-silver slurry collected in the cavity can be transported to the slurry transfer box 6 through the delivery pipe 15 by the slurry transfer pump, and then supplied to the spraying assembly 7 by the slurry transfer box 6, thereby realizing the recycling of the non-silver slurry, avoiding the waste of non-silver slurry, and further reducing the metallization cost of TOPCon batteries.

[0084] In one embodiment, Figure 4 As shown, two fixed plates 16 are arranged at one end of the transverse plate 10 away from the slurry transfer box 6, and a vertical sliding groove 17 is arranged on one side of the two fixed plates 16 close to each other. A sliding block is slidably arranged in the vertical sliding groove 17, and the upper end of the sliding block is connected to the top wall of the vertical sliding groove 17 through a first spring 18. A movable plate 19 is slidably arranged between the two fixed plates 16, and both ends of the movable plate 19 are respectively connected to the sliding block, a first magnetic block 20 is arranged on the upper surface of the movable plate 19, two mounting plates 21 are arranged on the lower surface of the movable plate 19, a pressure roller 22 is arranged between the two mounting plates 21, and the pressure roller 22 is rotatably connected to the mounting plate 21 through a rotating shaft, and a second magnetic block 23 is arranged on one side wall of the second electric push rod 11 close to the movable plate 19, the second magnetic block 23 is located above the first magnetic block 20, and the lower end of the second magnetic block 23 has the same magnetic pole as the upper end of the first magnetic block 20.

[0085] The working principle and beneficial effects of the above technical solution are as follows: when the viscosity of the non-silver paste is high, the flow resistance of the gas in the paste is very large. During the printing process, if the operation is improper, such as stirring, vibration, etc., air may be brought into the non-silver paste to form bubbles. If these bubbles are not discharged in time, they will form voids or defects in the main and auxiliary grids after printing, affecting the printing quality and subsequent processes, and reducing the quality of the main and auxiliary grids. Therefore, when the viscosity of the non-silver paste is high, the scraper 13 will be driven by the non-silver paste to slide backward when it contacts the non-silver paste, and the scraper 13 will drive the second electric push rod 11 to slide along the horizontal plate 10 away from the paste transfer box 6, the telescopic spring 12 will be stretched, and the second electric push rod 11 will drive the second magnetic block 23 It moves toward the direction approaching the movable plate 19. When the second magnetic block 23 moves to above the first magnetic block 20, due to the same magnetic pole as the upper end of the second magnetic block 23 and the first magnetic block 20, a repulsive force will be generated between the second magnetic block 23 and the first magnetic block 20. Through the magnetic force, the first magnetic block 20 drives the movable plate 19 to slide downward, and the slider drives the first spring 18 to stretch. The movable plate 19 drives the pressure roller 22 to move downward through the mounting plate 21, so that the pressure roller 22 contacts the non-silver paste slurry, further smoothes the non-silver paste slurry, and at the same time, the gas mixed in the non-silver paste slurry can be pressed out through the rolling process, thereby eliminating bubbles inside the non-silver paste slurry, avoiding defects such as pores formed inside the main and auxiliary grids, improving the preparation quality of the main and auxiliary grids, and ensuring the metallization quality of the TOPCon battery.

[0086] In one embodiment, Figure 6 As shown, first electric push rods 24 are symmetrically arranged at the bottom of the left and right sides of the limiting frame 8, one end of the first electric push rod 24 is connected to the upper surface of the printing platform 2, and the other end of the first electric push rod 24 is connected to the bottom of the limiting frame 8.

[0087] The working principle and beneficial effects of the above technical solution are as follows: the blue film 9 can be separated from the limiting frame 8 by extending the first electric telescopic rod, so that the processed blue film 9 can be easily removed from the printing platform 2.

[0088] In one embodiment, Figure 6As shown, the limit components are symmetrically arranged inside the left and right ends of the limit frame 8, and the limit components include a cross-arranged transverse slide 25 and a longitudinal slide 26. The transverse slide 25 is arranged horizontally, and one end of the transverse slide 25 is connected to the inside of the limit frame 8. The longitudinal slide 26 is arranged vertically, and one end of the longitudinal slide 26 is connected to the bottom of the limit frame 8. A gear column 27 is arranged at the intersection of the transverse slide 25 and the longitudinal slide 26. The front and rear ends of the gear column 27 are rotatably connected to the inner walls of the front and rear sides of the transverse slide 25 through a rotating shaft. A first rack 28 is horizontally arranged on the side of the gear column 27 close to the first electric push rod 24. The first rack 28 is meshed with the gear column 27. The first rack 28 is arranged on the sliding rod On the upper surface of 29, the sliding rod 29 is slidably connected to the inner wall of the horizontal slide groove 25 left and right, a sliding hole is set at one end of the sliding rod 29 close to the blue diaphragm 9, and a connecting rod 30 is slidably set in the sliding hole. The connecting rod 30 is connected to the inner wall of the sliding hole through a reset spring 31, and a limiting plate 32 is set at the end of the connecting rod 30 away from the sliding rod 29. The upper and lower sides of the limiting plate 32 are respectively slidably connected to the inner wall of the horizontal slide groove 25. A second rack 33 is set on the side of the gear column 27 close to the limiting plate 32. The second rack 33 is meshed with the gear column 27, and the side wall of the second rack 33 is slidably connected to the inner wall of the longitudinal slide groove 26 up and down, and the upper end of the second rack 33 is connected to the top wall of the longitudinal slide groove 26 through a connecting spring 34.

[0089] The working principle and beneficial effects of the above technical solution are as follows: after the blue diaphragm 9 is placed on the printing platform 2, the first electric push rod 24 is started, the first electric push rod 24 retracts to drive the limit frame 8 to move downward, the rear inner wall of the limit frame 8 contacts the rear side wall of the blue diaphragm 9, the blue diaphragm 9 is located between the two limit plates 32, the length of the limit plates 32 is not less than the length of the blue diaphragm 9, as the limit frame 8 moves downward, the second rack 33 gradually contacts the upper surface of the printing platform 2, the second rack 33 slides upward along the longitudinal slide groove 26, the connecting spring 34 is compressed, and the second rack 33 drives the gear column 27 to rotate, the gear column 27 drives the first rack 28 to slide along the transverse slot 25 toward the blue diaphragm 9, the first rack 28 drives the sliding rod 29 to slide along the inner wall of the transverse slot 25, the sliding rod 29 drives the connecting rod 30 to move through the reset spring 31, and the connecting rod 30 drives the limit plate 32 to slide toward the blue diaphragm 9 until the limit plate 32 contacts the side wall of the blue diaphragm 9, and then continues to control the limit frame 8 to move downward, the limit plate 32 slides downward along the outer wall of the blue diaphragm 9 until the upper surface of the limit plate 32 contacts the screen on the blue diaphragm 9 The vertical distance of the upper surface is equal to the preset thickness of the non-silver paste, the upper surface height of the limit plate 32 is higher than the upper surface height of the screen, and the limit frame 8 stops moving downward. At this time, when the scraper 13 performs the leveling operation, both ends of the scraper 13 are in contact with the upper surface of the limit plate 32, which can evenly level the non-silver paste, so that the non-silver paste is evenly spread on the upper surface of the screen, and the scraper 13 can scrape off the non-silver paste on the limit plate 32 to avoid residual waste of the non-silver paste. By setting the limit plate 32, the two sides of the blue diaphragm 9 can be limited so that the blue diaphragm 9 is kept in the center. In the limiting frame 8, the printing accuracy is improved, and the limiting plate 32 contacts the side wall of the blue diaphragm 9, which can prevent non-silver paste from flowing down from the gap between the blue diaphragm 9 and the limiting frame 8, thereby avoiding waste of non-silver paste. Moreover, by setting the reset spring 31, the distance between the sliding rod 29 and the limiting plate 32 can be adjusted, so that the limiting plate 32 can adapt to blue diaphragms 9 of different widths. When printing blue diaphragms 9 of different widths, there is no need to replace a new limiting frame 8, which improves the application range of the limiting frame 8 and further reduces the metallization cost of the TOPCon battery.

[0090] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0091] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0092] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A TOPCon battery metallization method, characterized in that: The following steps are involved: Step 1: providing a blue film (9); Step 2: preparing a metal seed layer on one side of the blue film (9) and then drying it; Step 3: preparing a metal seed layer on the other side of the blue film (9) and then drying or sintering it; Step 4: preparing the main and auxiliary gates on one side of the metal seed layer and then drying them. The main and auxiliary gates are made of non-silver paste; Step 5: Prepare the main and auxiliary grids on the other side of the metal seed layer and then sinter them to complete the metallization of the cell.

2. A TOPCon battery metallization method according to claim 1, characterized in that: The blue diaphragm (9) includes: A semiconductor substrate (901), wherein a tunneling layer (902) is disposed on a first surface of the semiconductor substrate (901); A first conductivity type semiconductor region (903) on the tunneling layer (902) contains impurities of the first conductivity type; Impurities of a second conductivity type opposite to the first conductivity type are located on the second surface of the semiconductor substrate (901) to form a second conductivity type semiconductor region (904) opposite to the first conductivity type semiconductor region (903); A first passivation film (905) on the first conductivity type semiconductor region (903); A first electrode (906) formed on the first passivation film (905) and connected to the first conductive type semiconductor region (903) through an opening formed in the first passivation film (905); A second passivation film A (907) on the second conductivity type semiconductor region (904); A second passivation film B (908) on the second passivation film A (907); A second electrode formed on the second passivation film B (908) and connected to the second conductivity type semiconductor region (904) through openings formed in the second passivation film B (908) and the second passivation film A (907); An isolation portion for preventing a first conductive type semiconductor region (903) from contacting a second conductive type semiconductor region (904), wherein the isolation portion does not include a tunneling layer (902) and the first conductive type semiconductor region (903), and is located at an edge portion of a first surface of a semiconductor substrate (901), and a first passivation film (905) covers the first surface of the semiconductor substrate (901) and the isolation portion.

3. A TOPCon battery metallization method according to claim 1, characterized in that: In step 2 and step 3, the metal seed layer includes but is not limited to a silver seed layer, a nickel seed layer, a silver-coated copper seed layer, and a silver-coated nickel seed layer.

4. A TOPCon battery metallization method according to claim 1, characterized in that: In step 4, the non-silver paste includes one or more of silver-coated copper paste, silver-coated aluminum paste, silver-coated nickel paste, and pure copper paste.

5. A TOPCon battery metallization method according to claim 1, characterized in that: In step 2 and step 3, the metal seed layer has a thickness of 0.05-5 μm and a width of 3-60 μm.

6. A TOPCon battery metallization method according to claim 3, characterized in that: The gate line layer of the metal seed layer is a single layer or multiple layers, the sintering temperature of the silver seed layer is 600-850°C, the sintering temperature of the nickel seed layer is 300-700°C, and the sintering temperature of the silver-coated copper seed layer and the silver-coated nickel seed layer is 400-850°C.

7. A TOPCon battery metallization method according to claim 1, characterized in that: The gate line layer of the main and auxiliary gates is a single layer or multiple layers.

8. A TOPCon battery metallization method according to claim 1, characterized in that: The main and auxiliary grids are prepared by any one of the processes of printing, electroplating, sputtering, spraying, coating, rolling, roll printing and transfer printing.

9. A TOPCon battery metallization method according to claim 1, characterized in that: In step 5, the battery cell is subjected to low temperature sintering, with the sintering temperature being 200-600°C.

10. A TOPCon battery metallization method according to claim 1, characterized in that: In step 5, the battery cell is sintered at a high temperature of 600-850°C.

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