Production process for small photovoltaic cell, and integrated production system for silicon wafer passivation film deposition and screen printing

Abstract

Provided in the present invention is a production process for a small photovoltaic cell. Further provided in the present invention is an integrated production system for silicon wafer passivation film deposition and screen printing. In the present invention, before screen printing, a complete silicon wafer semi-finished product is first cut into a plurality of small silicon wafers by means of non-destructive laser cutting; then, a chain passivation film deposition device is also used, and is mounted before screen printing so as to form an integrated device; and the cut small silicon wafers pass through a chain edge passivation film deposition device, and proceed to screen printing and sintering to form small cells. In the present invention, a chain atomic layer deposition (CALD) device is particularly used, and can realize seamless connection with the subsequent chain screen printing step; and a sintering machine is used to perform annealing and to activate the passivation effect of a passivation film, achieving the aim of reducing the recombination of a small number of carriers on a cutting surface, thereby achieving the aim of improving the photoelectric conversion efficiency of small cells and the power of encapsulated modules.

Description

A production process of small photovoltaic cells and an integrated production system for silicon wafer passivation film deposition and screen printing

[0001] The present application claims priority from a Chinese patent application filed on September 9, 2024, at the Chinese Patent Office, with application number 2024112605808, and with the title of "A production process of small photovoltaic cells and an integrated production system for silicon wafer passivation film deposition and screen printing", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application belongs to the technical field of photovoltaic cell preparation, and particularly relates to a production process of small photovoltaic cells and an integrated production system for silicon wafer passivation film deposition and screen printing. BACKGROUND

[0003] The existing multi-slice assembly, tile assembly or shingle assembly generally cuts the complete cell into multiple small cell batteries before packaging the assembly. The cutting surface of the small cell battery after cutting is a bare silicon surface. The bare silicon surface has many defects, and the surface charge is very serious, which affects the photoelectric conversion efficiency of the small cell battery, and further affects the power generation of the photovoltaic assembly packaged. Referring to FIG. 1, which is a process flow diagram of the small cell battery manufacturing and packaging into a photovoltaic assembly in the prior art. As disclosed in the prior art CN111430506A, the small cell battery is cut on the finished product and stacked together to passivate the cutting surface. However, since the finished product has surface electrodes, the height of the electrodes affects the tightness between the stacked pieces when stacked together, causing the passivation film to be deposited on the edge and also on the front or back of the cell, resulting in plating around. Since the passivation film is mostly an insulating film, when it covers the electrode surface, it will cause poor contact between the cells during assembly packaging, i.e., a virtual welding phenomenon, resulting in a decrease in the power generation of the assembly and extremely unstable reliability of the assembly. In order to activate the passivation effect of the passivation film, an additional annealing device is required, and high temperature and air contact during the annealing process can easily cause oxidation of the electrodes, resulting in an increase in the cost of small cell batteries and a decrease in the yield. Although there are also small silicon wafers obtained by cutting the complete silicon wafer before or during the cell manufacturing process in the prior art, the cell manufacturing process still needs to go through multiple heat treatment processes. The heat treatment equipment is mostly a tubular device, and the existing equipment and carriers do not match the size of the small silicon wafer, which will inevitably bring new problems such as increased cost or reduced production capacity.

[0004] Therefore, how to further improve the preparation method of small cell batteries, find a more suitable processing technology and device, and solve the above-mentioned problems existing in the prior art has become one of the problems to be solved by many front-line researchers in the industry. SUMMARY

[0005] Therefore, the present application aims to solve the technical problem of providing a production process of small piece photovoltaic cells, in particular, a new method for improving the passivation performance of small piece cells. The present application cuts the silicon wafer during the cell production process, and passivates the surface defects by depositing a passivation film on the cutting surface, thereby improving the efficiency of the cut small piece cell and the power of the packaged photovoltaic module. The present application does not pass through the tubular device after cutting, and the deposition of the passivation film is achieved by a chain device, which is perfectly compatible with the existing post-production process.

[0006] The present application provides a production process of small piece photovoltaic cells, comprising the following steps:

[0007] Step 1: providing a complete silicon wafer, the complete silicon wafer comprising a front surface and a back surface opposite to the front surface, and a side surface connecting the front surface and the back surface, and performing a photovoltaic cell production process on the complete silicon wafer before screen printing to obtain a complete silicon wafer semi-finished product;

[0008] Step 2: cutting the complete silicon wafer semi-finished product to obtain a plurality of small piece silicon wafers;

[0009] The side surface of the small piece silicon wafer has at least one cutting surface;

[0010] Step 3: performing chain atomic layer deposition on the small piece silicon wafer to deposit a passivation film only on the cutting surface to obtain a passivation film small piece silicon wafer;

[0011] Step 4: screen printing the passivation film small piece silicon wafer, and then sintering to obtain a small piece photovoltaic cell.

[0012] Preferably, the side length dimension of the complete silicon wafer is 155-230 mm;

[0013] The cutting method comprises laser cutting;

[0014] The small piece silicon wafer has oppositely arranged short edge portions and long edge portions, and the side length dimension of the short edge portion is 10-115 mm.

[0015] Preferably, the preparation process of the complete silicon wafer semi-finished product further comprises texturing, diffusion, edge and back surface treatment, and front surface and / or back surface passivation.

[0016] Preferably, the number of cutting surfaces of a single small piece silicon wafer is one or two.

[0017] Preferably, in step 3, the small piece silicon wafer is placed in a single or multiple front and back surface stacked manner.

[0018] Preferably, a plurality of small piece silicon wafers are stacked by a carrier.

[0019] Preferably, the chain atomic layer deposition is specifically depositing by using a chain atomic layer deposition device, the non-cutting surface of the small silicon piece is located in a gas curtain isolation zone formed by a protective gas, and the cutting surface is located in a passivation film reaction source deposition zone formed by a passivation film reaction source gas phase, and the passivation film deposition is performed;

[0020] The protective gas is specifically a gas that does not participate in the passivation film deposition reaction and a gas that does not react with the small silicon piece.

[0021] Preferably, the flow rate of the passivation film reaction source gas phase is greater than or equal to the flow rate of the protective gas;

[0022] The location is specifically that the front surface and / or the back surface of the small silicon piece is located in the gas curtain isolation zone formed by the protective gas from top to bottom;

[0023] The location is specifically that the passivation film reaction source gas phase forms a passivation film reaction source deposition zone from top to bottom, and the cutting surface is located on one side of the passivation film reaction source deposition zone perpendicular to the flow direction of the passivation film reaction source gas phase;

[0024] The gas curtain isolation zone is used to isolate the passivation film reaction source gas phase from contacting the non-cutting surface of the small silicon piece during the passivation film reaction source deposition process;

[0025] The gas curtain isolation zone fills the entire chain atomic layer deposition chamber except the passivation film reaction source deposition zone.

[0026] Preferably, the passivation film deposition is specifically an alternating single or multiple cycle deposition of the passivation film reaction source to form the passivation film;

[0027] The alternating single deposition is specifically that the cutting surface first enters a passivation film first reaction source deposition zone to deposit a first reaction source, then enters a gas curtain isolation zone, and then sequentially enters a passivation film Nth reaction source deposition zone to deposit an Nth reaction source for reaction to form the passivation film; wherein N is greater than or equal to 2;

[0028] The alternating multiple deposition is specifically that the cutting surface first enters a passivation film first reaction source deposition zone to deposit a first reaction source, then enters a gas curtain isolation zone, and then sequentially enters a passivation film Nth reaction source deposition zone to deposit an Nth reaction source for reaction to form a single-layer passivation film, and then enters the gas curtain isolation zone, and then enters another passivation film first reaction source deposition zone to repeat the above steps to form the passivation film; wherein N is greater than or equal to 2;

[0029] The chain atomic layer deposition is specifically that the small silicon pieces are transported by a conveying device and sequentially subjected to the passivation film deposition.

[0030] Preferably, the screen printing comprises chain screen printing;

[0031] The chain atomic layer deposition and the chain screen printing are connected by chain conveying, and the passivation film small piece silicon wafer is conveyed to a screen printing feeding position for the screen printing, and the chain atomic layer deposition and the chain screen printing form an integrated continuous production process;

[0032] The passivation film comprises an aluminum oxide passivation film;

[0033] The passivation film is a hydrogen-rich film, and the passivation film is passivated simultaneously in the sintering process.

[0034] The application further provides an integrated production system for passivation film deposition and screen printing of a silicon wafer, comprising a chain atomic layer deposition device and a screen printing device connected with the chain atomic layer deposition device.

[0035] The chain atomic layer deposition device comprises a conveying device and an atomic layer deposition device.

[0036] The atomic layer deposition device is provided with a gas curtain isolation area and a passivation film reaction source deposition area.

[0037] Preferably, the screen printing device comprises a chain screen printing device.

[0038] The chain screen printing device comprises a chain screen printing conveying device.

[0039] The chain atomic layer deposition device is connected with the chain screen printing conveying device through the conveying device, forming the integrated continuous production system for passivation film deposition and screen printing.

[0040] The conveying device comprises a conveying belt, an upper and lower feeding structure at both ends of the conveying belt, and a connecting structure with the chain screen printing conveying device.

[0041] Preferably, the gas curtain isolation area is arranged perpendicularly to the conveying belt of the conveying device.

[0042] The passivation film reaction source deposition area is arranged perpendicularly to the conveying belt of the conveying device.

[0043] A plurality of first spray holes and a plurality of second spray holes are arranged on the chain atomic layer deposition device above the conveying belt; and a plurality of gas outlet holes are arranged on the chain atomic layer deposition device below the conveying belt.

[0044] The first spray holes blow out passivation film reaction sources to form the passivation film reaction source deposition area, and the second spray holes blow out protective gases to form the gas curtain isolation area.

[0045] The distance between the first spray hole and the silicon wafer is less than or equal to the distance between the second spray hole and the silicon wafer.

[0046] Preferably, the passivation film reaction source deposition area comprises a plurality of passivation film different reaction source deposition areas, or a plurality of passivation film same reaction source deposition areas and a plurality of passivation film different reaction source deposition areas.

[0047] The gas curtain isolation area is arranged between the plurality of passivation film different reaction source deposition areas.

[0048] The gas curtain isolation area is arranged between the plurality of passivation film same reaction source deposition areas.

[0049] The present application provides a production process of small piece photovoltaic cell, comprising the following steps: step 1: providing a complete silicon wafer, the complete silicon wafer comprising a front surface and a back surface opposite to the front surface, and a side surface connecting the front surface and the back surface, and performing a photovoltaic cell production process on the complete silicon wafer before screen printing to obtain a complete silicon wafer semi-finished product; step 2: cutting the complete silicon wafer semi-finished product to obtain a small piece silicon wafer; the side surface of the small piece silicon wafer has a single or two cutting surfaces; step 3: using chain atomic layer deposition on the small piece silicon wafer to deposit a passivation film only on the cutting surface to obtain a passivation film small piece silicon wafer; step 4: screen printing the passivation film small piece silicon wafer, and then sintering to obtain a small piece photovoltaic cell. Compared with the prior art, the present application provides a preparation method of crystalline silicon small piece cell with specific steps and specific equipment. Before screen printing, the present application uses laser non-destructive cutting to cut a whole complete silicon wafer into a plurality of small piece silicon wafers, and then simultaneously uses a chain passivation film deposition equipment installed in a screen printing pre-formed integrated equipment to pass the small piece silicon wafer after cutting through the chain edge passivation film deposition equipment into screen printing and sintering to form a small piece cell. The present application particularly uses a chain atomic layer deposition device (Chain Atomic Layer Deposition, CALD for short) which can be seamlessly connected with the subsequent chain screen printing step, utilizes a sintering machine to perform annealing and activate the passivation effect of the passivation film, achieves the purpose of reducing the minority carrier recombination of the cutting surface, and thus achieves the purpose of improving the photoelectric conversion efficiency of the small piece cell and the power of the module formed by packaging.

[0050] The present application is in the photovoltaic cell manufacturing link, to the silicon wafer before screen printing in the cell process, cutting and cutting into small pieces of silicon wafer, and the cutting surface of small piece of silicon wafer is deposited passivation film to passivate its defects, so as to improve the small piece of cell photoelectric conversion efficiency, improve the effect of power generation of packaged photovoltaic module, the present application scheme is not through the pipe type equipment after cutting, and the deposition passivation film equipment is chain type equipment, and the existing back-end mass production process is perfectly matched. The present application can be applied to various crystalline silicon solar cells, not limited to PERC, TOPCon cell and the like. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 is a process flow diagram of the prior art small piece of cell manufacturing and packaging into photovoltaic module;

[0052] Fig. 2 is a process flow diagram provided by the present application;

[0053] Fig. 3 is a schematic diagram of the structure of the chain passivation equipment provided by the present application;

[0054] Fig. 4 is a schematic diagram of the structure of the chain atomic layer deposition device provided by the present application. DETAILED DESCRIPTION

[0055] In order to further understand the present application, the preferred embodiments of the present application are described below in conjunction with examples, but it should be understood that these descriptions are only to further illustrate the features and advantages of the present application, and are not limitations on the claims of the present application.

[0056] All raw materials of the present application are not particularly limited in source, and can be purchased on the market or prepared according to conventional methods known to those skilled in the art.

[0057] The purity of the raw materials used in the present application is not particularly limited, and the present application preferably has the conventional purity in the field of electronic pure or small piece of photovoltaic cell preparation.

[0058] The grade and abbreviation of all materials of the present application belong to the conventional grade and abbreviation in the art, and each grade and abbreviation is clear and explicit in the field of its related use. Those skilled in the art can purchase or prepare by conventional method according to the grade, abbreviation and corresponding use.

[0059] The abbreviation of all processes of the present application belongs to the conventional abbreviation in the art, and each abbreviation is clear and explicit in the field of its related use. Those skilled in the art can understand the conventional process steps according to the abbreviation.

[0060] The present application provides a production process of small piece of photovoltaic cell, which comprises the following steps:

[0061] Step 1: providing a complete silicon wafer including a front surface and a back surface opposite to the front surface, and a side surface connecting the front surface and the back surface, and performing a photovoltaic cell production process on the complete silicon wafer before screen printing to obtain a complete silicon wafer semi-product;

[0062] Step 2: cutting the complete silicon wafer semi-product to obtain a plurality of small silicon wafers;

[0063] The side surface of the small silicon wafer has at least one cutting surface;

[0064] Step 3: performing chain atomic layer deposition on the small silicon wafer to deposit a passivation film only on the cutting surface to obtain a passivation film small silicon wafer;

[0065] Step 4: screen printing the passivation film small silicon wafer and then sintering to obtain a small photovoltaic cell.

[0066] The present application first provides a complete silicon wafer including a front surface and a back surface opposite to the front surface, and a side surface connecting the front surface and the back surface, and performing a photovoltaic cell production process on the complete silicon wafer before screen printing to obtain a complete silicon wafer semi-product; then cutting the complete silicon wafer semi-product to obtain a plurality of small silicon wafers; wherein the side surface of the small silicon wafer has at least one cutting surface, preferably one or two cutting surfaces.

[0067] In the present application, the side length dimension of the complete silicon wafer is preferably 155-230 mm, more preferably 170-220 mm, and more preferably 180-210 mm.

[0068] In the present application, the cutting method preferably includes laser cutting.

[0069] In the present application, the small silicon wafer has oppositely arranged short edge portions and long edge portions, and the side length dimension of the short edge portion is preferably 10-115 mm, more preferably 30-100 mm, and more preferably 50-80 mm.

[0070] In the present application, the preparation process of the complete silicon wafer semi-product preferably further includes texturing, diffusion, edge and back surface treatment, front surface and / or back surface passivation. Specifically, texturing is performed to form a non-flat silicon wafer surface to enhance light incidence effect; diffusion is performed to form a PN junction to produce photo-generated carriers under light; edge and back surface treatment includes etching and alkali etching to remove the PN junction of the edge and back surface of the silicon wafer and form a relatively flat silicon wafer back surface structure; front surface and / or back surface passivation selects passivation process and film layer material according to different structure cells, such as depositing a silicon nitride layer on the front and back surfaces, which is not limited herein.

[0071] The small silicon wafer is deposited with a passivation film by chain atomic layer deposition only on the cutting surface to obtain a passivation film small silicon wafer.

[0072] In the present application, the small silicon wafer placement preferably includes single or multiple front and back surface stacking placement, more preferably multiple front and back surface stacking placement is achieved by a carrier, specifically, multiple small silicon wafers can be placed in the carrier to achieve stacking, further, the carrier can be provided with an opening and a closed surface, the cutting surface is placed corresponding to the opening of the carrier, and the remaining non-coating surface is placed corresponding to the closed surface of the carrier, so as to better reduce the around plating of the non-coating surface; the carrier can also be a fixing device to fix the stacking of the silicon wafers, and the specific structure is not limited here.

[0073] In the present application, the chain atomic layer deposition can be performed by using a chain atomic layer device (chain atomic layer deposition device), the non-cutting surface of the small silicon wafer is located in a gas curtain isolation zone formed by a protective gas, and the cutting surface is located in a passivation film reaction source deposition zone formed by a passivation film reaction source gas phase, and the passivation film deposition is performed.

[0074] In the present application, the protective gas can be a gas that does not participate in the passivation film deposition reaction and does not react with the small silicon wafer. At the same time, the protective gas does not react with the commonly used materials such as metals and rubbers in the device.

[0075] In the present application, the flow rate of the passivation film reaction source gas phase is preferably greater than or equal to the flow rate of the protective gas, and more preferably greater than the flow rate of the protective gas, so as to reduce the influence of the gas curtain formed by the protective gas on the reaction source gas phase.

[0076] In the present application, the location can be that the front surface and / or the back surface of the small silicon wafer faces upward and is located in the gas curtain isolation zone formed by the protective gas from top to bottom.

[0077] In the present application, the location can be that the passivation film reaction source gas phase forms a passivation film reaction source deposition zone from top to bottom, and the cutting surface is preferably located on one side of the passivation film reaction source deposition zone perpendicular to the flow direction of the passivation film reaction source gas phase.

[0078] In the present application, the gas curtain isolation zone is preferably used to isolate the passivation film reaction source deposition process, and the passivation film reaction source gas phase preferably contacts the non-cutting surface of the small silicon wafer.

[0079] In the present application, the gas curtain isolation zone is preferably filled with the entire chain atomic layer deposition chamber except the passivation film reaction source deposition zone.

[0080] In the present application, the deposition of the passivation film can be specifically the deposition of the passivation film by alternately single or multiple cycles of the passivation film reaction source, and more preferably the deposition of the passivation film by alternately multiple cycles of the passivation film reaction source.

[0081] In the present application, the alternately single deposition can be specifically that the cutting surface is first deposited with the first reaction source in the passivation film first reaction source deposition area, then enters the gas curtain isolation area, and then sequentially enters the passivation film Nth reaction source deposition area to deposit the Nth reaction source for reaction to form the passivation film; wherein N is greater than or equal to 2.

[0082] In the present application, the alternately multiple deposition can be specifically that the cutting surface is first deposited with the first reaction source in the passivation film first reaction source deposition area, then enters the gas curtain isolation area, and then sequentially enters the passivation film Nth reaction source deposition area to deposit the Nth reaction source for reaction to form a single-layer passivation film, and then enters the gas curtain isolation area and then enters another passivation film first reaction source deposition area to repeat the above steps to form the passivation film; wherein N is greater than or equal to 2.

[0083] In the present application, the chain atomic layer deposition can be specifically that the single or multiple stacked small silicon pieces are transported by a conveying device and sequentially deposited with the passivation film.

[0084] In the present application, the passivation film preferably includes an aluminum oxide passivation film.

[0085] In the present application, the passivation film is preferably a hydrogen-rich film, and the passivation film will be passivated simultaneously during the sintering process.

[0086] Finally, the passivation film small silicon piece is screen printed and sintered to obtain a small photovoltaic cell.

[0087] In the present application, the screen printing preferably includes chain screen printing.

[0088] In the present application, the chain atomic layer deposition and the chain screen printing preferably transport the passivation film small silicon piece to the screen printing loading position by chain conveying for the screen printing, and the chain atomic layer deposition and the chain screen printing form an integrated continuous production process.

[0089] The present application also provides an integrated production system for the deposition and screen printing of a silicon passivation film, comprising a chain atomic layer deposition device and a screen printing device connected to the chain atomic layer deposition device.

[0090] The chain atomic layer deposition device comprises a conveying device and an atomic layer deposition device.

[0091] The atomic layer deposition device is provided with a gas curtain isolation area and a passivation film reaction source deposition area.

[0092] In the present application, the screen printing device preferably comprises a chain screen printing device.

[0093] In the present application, the chain screen printing device preferably comprises a chain screen printing conveying device.

[0094] In the present application, the chain atomic layer deposition device is preferably connected to the chain screen printing conveying device through the conveying device, forming an integrated continuous production system of passivation film deposition and screen printing.

[0095] In the present application, the conveying device preferably comprises a conveying belt, a feeding and discharging structure at both ends of the conveying belt, and a connecting structure with the chain screen printing conveying device.

[0096] In the present application, the gas curtain isolation area is preferably arranged perpendicular to the conveying belt of the conveying device.

[0097] In the present application, the passivation film reaction source deposition area is preferably arranged perpendicular to the conveying belt of the conveying device.

[0098] In the present application, a plurality of first spray holes and a plurality of second spray holes are preferably arranged on the chain atomic layer deposition device above the conveying belt; a plurality of gas outlet holes are arranged on the chain atomic layer deposition device below the conveying belt. Specifically, the first spray holes comprise upper reaction source gas phase spray holes, and the second spray holes comprise upper gas curtain spray holes.

[0099] In the present application, the diameter of the upper gas curtain spray holes is preferably 1-3 mm, more preferably 1.2-2.8 mm, and more preferably 1.5-2.5 mm. The diameter of the upper reaction source gas phase spray holes is preferably 1-3 mm, more preferably 1.2-2.8 mm, and more preferably 1.5-2.5 mm.

[0100] In the present application, the density value of the gas curtain area of the upper gas curtain spray holes is 1-3 / cm 2 , more preferably 2-3 / cm 2 . The density value of the reaction source area of the upper reaction source gas phase spray holes is 1-3 / cm 2 , more preferably 2-3 / cm 2 .

[0101] In the present application, the diameter of the lower gas outlet is preferably 4-5 cm, more preferably 4.2-4.8 cm, and more preferably 4.4-4.6 cm. Among them, the gas outlet is large and does not have a hole diameter density.

[0102] In the present application, the first spray hole blowing out the passivation film reaction source preferably forms the passivation film reaction source deposition area.

[0103] In the present application, the second spray hole blowing out the protective gas preferably forms the gas curtain isolation area.

[0104] In the present application, the distance between the first spray hole, i.e. the spray hole blowing out the passivation film reaction source (reaction source gas phase spray hole), and the silicon wafer is preferably less than or equal to the distance between the second spray hole, i.e. the spray hole blowing out the protective gas (upper gas curtain spray hole), and the silicon wafer. Specifically, the difference between the distance between the first spray hole and the silicon wafer and the distance between the second spray hole and the silicon wafer is preferably 5-20 mm, more preferably 8-18 mm, and more preferably 10-15 mm. That is, the distance between the passivation film reaction source spray hole and the silicon wafer is closer, so as to reduce the influence of the protective gas on the reaction source gas phase.

[0105] In the present application, the passivation film reaction source deposition area preferably comprises a plurality of passivation film different reaction source deposition areas. Alternatively, in the present application, there are a plurality of passivation film same reaction source deposition areas and a plurality of passivation film different reaction source deposition areas.

[0106] In the present application, the gas curtain isolation area is preferably arranged between the plurality of passivation film different reaction source deposition areas.

[0107] In the present application, the gas curtain isolation area is preferably arranged between the plurality of passivation film same reaction source deposition areas.

[0108] Before screen printing, the present application uses laser non-destructive cutting to cut a whole piece of complete silicon wafer semi-finished product into a plurality of small pieces of silicon wafer, and simultaneously uses a chain passivation film deposition device to form an integrated device before screen printing, so that the cut small pieces of silicon wafer pass through the chain passivation film deposition device, the screen printing device and the sintering device in sequence to form small piece batteries. In the present application, the chain passivation film deposition device adopts a chain atomic layer deposition device. Further, the cutting and slicing are performed after the silicon nitride film on the front and back surfaces is plated and before screen printing, so as to avoid passing through the heat treatment tube device, seamlessly connect with the subsequent screen printing step, activate the passivation effect of the passivation film on the cutting surface through sintering, and the small piece battery forming mode of the present application can be perfectly combined with the existing process and device. The present application also provides a chain atomic layer deposition device with a specific structure.

[0109] The present application is to the cutting surface of small silicon wafer, using only the deposition of edge cutting surface chain device for passivation film deposition, chain device is a special structure design, can achieve only the deposition of cutting edge cutting surface effect, at the same time using and silk screen printing, sintering as chain device, can be integrated together, and using sintering machine platform for annealing activation passivation film passivation effect, to reduce the purpose of cutting surface minority carrier recombination, improve the passivation effect, so as to improve the purpose of small piece of battery photoelectric conversion efficiency and the power of the assembly formed by packaging.

[0110] The present application is to the cutting surface of small silicon wafer, using only the deposition of edge cutting surface chain device for passivation film deposition, chain device is a special structure design, can achieve only the deposition of cutting edge cutting surface effect, at the same time using and silk screen printing, sintering as chain device, can be integrated together, and using sintering machine platform for annealing activation passivation film passivation effect, to reduce the purpose of cutting surface minority carrier recombination, improve the passivation effect, so as to improve the purpose of small piece of battery photoelectric conversion efficiency and the power of the assembly formed by packaging.

[0111] The present application is to the cutting surface of small silicon wafer, using only the deposition of edge cutting surface chain device for passivation film deposition, chain device is a special structure design, can achieve only the deposition of cutting edge cutting surface effect, at the same time using and silk screen printing, sintering as chain device, can be integrated together, and using sintering machine platform for annealing activation passivation film passivation effect, to reduce the purpose of cutting surface minority carrier recombination, improve the passivation effect, so as to improve the purpose of small piece of battery photoelectric conversion efficiency and the power of the assembly formed by packaging.

[0112] The present application can be applied to a variety of crystalline silicon solar cells, not limited to PERC, TOPCon cell and the like, and the following will introduce the present application by taking the currently industrialized mainstream TOPCon cell as an example.

[0113] Taking the TOPCon cell as an example, the substrate is n-type silicon wafer in structure, the p+ doped layer is obtained by boron diffusion on the front surface, the n+ doped layer is obtained by in-situ phosphorus doping or intrinsic phosphorus diffusion on the back surface after depositing the tunnel oxide layer and polycrystalline silicon; and the AlO X layer is deposited on the front surface, and the silicon nitride layer is deposited on the front and back surfaces; the corresponding metal electrode is obtained by silk screen printing and sintering. The general process flow includes: texturing, boron diffusion, etching, alkali etching, depositing the tunnel oxide layer and polycrystalline silicon, back phosphorus doping, annealing, RCA cleaning, front AlO X , front and back deposition of silicon nitride, chain silk screen printing and sintering, to form the TOPCon cell.

[0114] The present application is to the cutting surface of small silicon wafer, using only the deposition of edge cutting surface chain device for passivation film deposition, chain device is a special structure design, can achieve only the deposition of cutting edge cutting surface effect, at the same time using and silk screen printing, sintering as chain device, can be integrated together, and using sintering machine platform for annealing activation passivation film passivation effect, to reduce the purpose of cutting surface minority carrier recombination, improve the passivation effect, so as to improve the purpose of small piece of battery photoelectric conversion efficiency and the power of the assembly formed by packaging.

[0115] In the battery manufacturing process, after the silicon nitride layer of the front and back surfaces is made, a complete silicon wafer is cut into two or more small silicon wafers by laser cutting, and the small silicon wafers after cutting are sequentially subjected to chain atomic layer deposition equipment, chain screen printing and sintering to form small battery cells.

[0116] 1. After the silicon nitride layer of the complete silicon wafer is deposited on the front and back surfaces, the complete silicon wafer semi-finished product is cut into multiple small silicon wafers by laser;

[0117] 2. The small silicon wafers are deposited with a passivation film on the cutting surface, and the small silicon wafers are subjected to passivation film deposition equipment that only deposits the cutting surface in a fixed area to deposit a passivation film on the cutting surface, thereby forming a passivation film small silicon wafer; chain atomic layer deposition equipment is preferably used, and the chain atomic layer deposition equipment and the screen sintering equipment form an integrated device;

[0118] 3. The passivation film small silicon wafer is subjected to screen printing and sintering to prepare positive and negative electrodes, and the edge-deposited passivation film can be annealed and passivated and activated during high-temperature sintering;

[0119] 4. The passivation film small silicon wafer forms a small battery cell.

[0120] The small battery cell prepared by the scheme of the present application passivates the cutting surface of bare silicon, improves the photoelectric conversion efficiency of the small battery cell, and further improves the power generation of the packaged photovoltaic module.

[0121] Referring to FIG. 2, FIG. 2 is a process flow diagram provided by the present application.

[0122] The present application passivates the cutting edge of the small silicon wafer after cutting by using a chain device that only deposits the cutting edge to deposit a passivation film, the chain device is specially designed, can only deposit the cutting surface, and at the same time, the screen printing and sintering are also chain devices, which can be integrated together, and the sintering machine is used for annealing and activating the passivation film on the cutting surface to achieve the purpose of reducing the recombination of minority carriers on the cutting surface, improve the passivation effect, and thus improve the photoelectric conversion efficiency of the battery and the power of the packaged module.

[0123] Specifically, in order to form a good metallization contact between silicon and metal electrode, the sintering furnace is usually provided with a short high temperature zone (such as 15 seconds 700-850-650℃ temperature zone), which can promote the diffusion of H in the passivation film on the cutting surface to the cutting surface through high temperature, saturate the dangling bond on the cutting surface, and further improve the field passivation effect of the passivation film on the cutting surface.

[0124] Specifically, the cutting surface of the small wafer after cutting is deposited with a passivation film by a chain atomic layer deposition device, which is integrated into the integrated continuous production device before the silk screen feeding, i.e., the process is feeding→passivation film deposition→silk screen feeding, and the chain atomic layer deposition device is chain atomic layer deposition (CALD), which is a thin film deposition technology based on the principle of atomic layer deposition (ALD), but compared with traditional ALD, CALD separates the regions of different sources in the chain space to occur different chemical reactions, instead of separating in time. CALD can be carried out at atmospheric pressure, and the growth rate can be significantly improved, reaching multiple orders of magnitude of traditional ALD. When the small wafer after cutting is deposited with a passivation film by CALD, the cutting surface, i.e., the cutting edge, is deposited with a passivation film, so as to avoid depositing the passivation film on the non-cutting surface side and the front and back surfaces of the small wafer. Therefore, the cutting surface area and the non-coating area are separated in the design of the CALD device. Since the small wafer needs to be moved on the CALD, the gas curtain is used to isolate the deposition area and the non-deposition area in the same space, but the two areas are isolated by the gas curtain. The gas curtain can use gas that does not participate in the deposition reaction, including but not limited to inert gases such as nitrogen and helium.

[0125] Specifically, the process and equipment of the chain atomic layer deposition (CALD) used in the present application for depositing a passivation film can include the following contents:

[0126] The deposited passivation film includes but is not limited to aluminum oxide, silicon oxide and other films that can passivate the bare silicon surface formed due to cutting and reduce carrier recombination centers.

[0127] Specifically, the present application takes the aluminum oxide film as an example, and the chain atomic layer deposition device shown in the present application mainly consists of a transmission part and a deposition part.

[0128] Specifically, the transmission part consists of a transmission belt, which can be a metal guide rail, a belt, etc., and the feeding and discharging structures at both ends of the transmission belt, as well as the connection structure with the silk screen printing device, for transporting the single small wafer or the stacked pieces of multiple small wafers after cutting, the transmission belt speed can be set according to specific needs, which is not limited here, and the transmission speed can be 0.01-1 m / min; the deposition part is divided into a gas curtain isolation area and a passivation film reaction source deposition area, the gas curtain is generally an inert gas, including but not limited to nitrogen, helium and the like, which is used to isolate the passivation film reaction source deposition area and the transmission part, so that the deposition reactants do not contact the non-coating area, avoiding the occurrence of the wrap condition.

[0129] Specifically, the deposition part of the reaction source coating area is divided into multiple small areas, each small area is different reaction source / material, and a gas curtain is used for isolation. In the deposition area of the passivation film, the present application takes the deposition of aluminum oxide and silicon oxide as an example: when the deposited passivation film is aluminum oxide, TMA (trimethylaluminum, same below) and H2O (pure water, resistivity > 18 MΩ, same below) or TMA and O3 are used as reaction source / material for cyclic deposition in the transport direction.

[0130] Specifically, the present application uses TMA and H2O as reaction material for deposition, and the small areas of the passivation film deposition area are TMA and H2O in turn, i.e. TMA-H2O-TMA-H2O and multiple small areas, and the rest are gas curtain isolation areas. The role of the gas curtain isolation area is not only to isolate the two reaction sources to avoid contact, but also to isolate the coating area from the non-coating area, so that they are completely isolated, achieving the purpose of depositing only the cutting surface. TMA and H2O can be provided by nitrogen carrying or saturated vapor pressure.

[0131] Specifically, the present application uses the method of carrying TMA and H2O source by nitrogen to illustrate, and the specific steps are as follows: the transmission belt carries the small silicon wafer after cutting, when passing through the TMA area, TMA chemisorbs on the cutting surface, and the factors affecting this step are the flow rate of the nitrogen carrying TMA source and the transmission belt speed. The flow rate of the nitrogen carrying source ranges from 0 to 10000 sccm, and the transmission belt speed is 0.01-1 m / min. After passing through the TMA area, the transmission belt continues to carry the small silicon wafer to the front, enters the H2O area, and there is a gas curtain isolation area between the TMA reaction source area and the H2O reaction source area, which can isolate the direct reaction of TMA and H2O during transportation. The factors affecting this step are the flow rate of the nitrogen carrying H2O source and the transmission speed, and the flow rate ranges from 0 to 10000 sccm, and the transmission belt speed is 0.01-1 m / min. This is a layer of aluminum oxide deposition, and subsequent cyclic deposition is carried out in this area with the transportation of the conveying belt; the number of cycles is 1-1000, which can be set as needed, and is not limited herein. The size of each TMA reaction source area and H2O reaction source area in the forward direction of the transmission belt is 5-210 mm, and the size in the vertical direction of the transmission belt is 5-20 mm. The size of this area can be set by designing the area of the relevant reaction source.

[0132] Specifically, when the deposited passivation film is silicon oxide, the deposition method is the same as above, and TMA is replaced by an organic silicon source (such as silane), and H2O is replaced by remote plasma oxygen generated by an ozone generator, i.e. the type of passivation film can be quickly switched by replacing the type of reaction material in the deposition coating area.

[0133] Specifically, the passivation film is an H-rich film, and H in the passivation film can diffuse to the cutting surface at high temperature in the sintering process, further improving the passivation effect of the passivation film.

[0134] In the present application, the cutting surface is isolated from the gas curtain isolation zone and the reaction zone by the chain atomic layer deposition device, so that the passivation film is deposited only on the edge cutting surface.

[0135] The present application provides a preparation method for small silicon wafer cells with specific steps and specific equipment. After the deposition of the front and back film silicon nitride, the complete silicon wafer semi-finished product is cut into multiple small silicon wafers using laser non-destructive cutting before screen printing. Then, a chain passivation film deposition device is used to form an integrated device before screen printing. The small silicon wafers after cutting are put into the screen printing and sintering to form small cell batteries. The present application particularly uses a chain atomic layer deposition device (CALD) to achieve seamless connection with the subsequent chain screen printing step. Annealing and activation of the passivation effect of the passivation film are performed on the sintering machine to reduce the recombination of minority carriers on the cutting surface, thereby improving the photoelectric conversion efficiency of the small cell battery and the power of the assembled components.

[0136] In the present application, the chain atomic layer deposition device, the chain screen printing device and the sintering device form an integrated device.

[0137] The structure of the chain passivation device (chain atomic layer deposition) provided by the present application is shown in Figure 3. Figure 3 is a schematic diagram of the structure of the chain passivation device provided by the present application.

[0138] In the passivation film deposition device schematic diagram of Figure 3, the single small silicon wafer or multiple small silicon wafers after cutting are stacked in the carrier or fixing device and transported on the transmission belt. The silicon wafer to be plated film area (i.e. cutting surface) is exposed to the chamber film plating area. The diagram shows only one cutting surface, and in fact there may be two cutting surfaces, i.e. the side opposite to the cutting surface in Figure 3 is also a cutting surface side.

[0139] Referring to Figure 4, Figure 4 is a schematic diagram of the structure of the chain atomic layer deposition device provided by the present application. In the detailed schematic diagram of the chain atomic layer deposition device of Figure 4, the position corresponding to the reaction source TMA\H2O is the cutting surface side of the small silicon wafer, and the diagram shows a single cutting surface.

[0140] As shown in the top view of Fig. 4, the points in the schematic diagram respectively represent the spray holes from which the gas of the corresponding area can be blown out, the spray hole corresponding to the reaction source TMA\H2O is the first spray hole, and the spray hole corresponding to N2 is the second spray hole. As shown in the top view, the chamber is divided into a gas curtain isolation area and a reaction source area, and the reaction source area is further divided into a TMA area and an H2O area. The gas curtain isolation area fills the entire chamber except the reaction source area. Generally, an inert gas is used to form the gas curtain isolation area, and N2 with a purity of 99.9999% is used in the present application. The purpose of filling the entire chamber with the gas curtain isolation area is to completely isolate the chamber from the outside and to fix the reaction source area in the corresponding area in the forward direction of the cutting surface to form a cutting surface reaction area, so as to completely separate the cutting surface reaction area from the area without coating and achieve the purpose of directional deposition of the passivation film.

[0141] The above content of the present application provides a new method for improving the passivation performance of small piece batteries and an integrated production system for deposition and screen printing of passivation films of silicon wafers. The present application uses a chain atomic layer deposition device (CALD) to deposit passivation films on the cutting surface of the small piece silicon wafer after cutting in a directional manner. The advantage is that the deposition on the specified side can be realized, and the screen printing and sintering are chain devices which can be integrated together. The annealing and activation of the passivation film passivation effect are performed by using the sintering machine table, so as to reduce the recombination of minority carriers on the cutting surface and improve the photoelectric conversion efficiency of the small piece battery and the power of the assembled component. Moreover, the small piece battery forming method of the present application can be perfectly combined with the existing process and equipment. Compared with other small piece battery forming or passivation methods, the present application has advantages.

[0142] The present application uses a CALD device to fix the reaction source area in the specific area in the forward direction during transportation by a unique gas curtain isolation area and reaction source area design, so as to achieve the purpose of depositing only on the cutting surface. At the same time, by designing the reaction source area as a gas curtain isolation area, the purpose of isolating different reaction source areas and isolating the coating area and the non-coating area of the cutting surface is achieved. The present application is used in the photovoltaic cell manufacturing link. The silicon wafer before screen printing in the battery process is cut into small piece silicon wafers, and the small piece silicon wafer cutting surface is deposited with a passivation film to passivate its defects, so as to improve the efficiency of the cut small piece battery and the power of the packaged photovoltaic module. The present application does not pass through a tubular device after cutting, and the deposition passivation film device is a chain device, which is perfectly combined with the existing back-end mass production process.

[0143] In order to further illustrate the present application, the production process of a small piece of photovoltaic cell and an integrated production system for silicon wafer passivation film deposition and screen printing provided by the present application are described in detail below in conjunction with examples, but it should be understood that these examples are implemented on the premise of the technical scheme of the present application, and detailed implementation modes and specific operation processes are given, which are only for further illustrating the features and advantages of the present application, and not for limiting the claims of the present application, and the protection scope of the present application is not limited to the following examples.

[0144] Taking a TOPCon cell as an example, in the manufacturing process of the TOPCon cell, after the silicon nitride is deposited on the front and back surfaces by the conventional production process, the wafer is sequentially subjected to texturing, boron diffusion, etching, alkali etching, deposition of a tunnel oxide layer and a phosphorus-doped polysilicon layer, RCA cleaning, deposition of AlO X , and deposition of silicon nitride on the front and back surfaces, and the process of each step and the implementation mode are as follows:

[0145] Texturing: an alkaline solution is used in a tank-type texturing device to perform texturing treatment on an n-type silicon wafer with a size of 182mm*182mm to form a pyramid-shaped texture to enhance light incidence effect.

[0146] Boron diffusion: a boron diffusion process is performed on the front surface of the n-type silicon wafer after texturing in a tubular boron diffusion furnace tube to form a PN junction and form a borosilicon glass layer on the surface of the silicon wafer.

[0147] Etching: single-sided etching treatment is performed on the back surface of the silicon wafer after boron diffusion in a chain cleaning machine to remove the borosilicon glass layer on the back surface.

[0148] Alkali etching: an alkaline solution is used to treat the back surface of the silicon wafer to form a relatively flat back surface structure of the silicon wafer.

[0149] Deposition of a tunnel oxide layer and a phosphorus-doped polysilicon layer: a tubular PECVD is used to deposit a tunnel oxide layer, doped amorphous silicon film and silicon oxide mask on the back surface of the silicon wafer, and then the wafer is put into a quartz tube in an annealing step sequence in a high-temperature nitrogen atmosphere to crystallize the amorphous silicon into polysilicon and activate the doped atoms in the polysilicon film to form an effectively doped polysilicon film.

[0150] RCA cleaning: the phosphosilicate glass formed on the front and side surfaces of the silicon wafer is removed, and the excess polysilicon plating on the front and side surfaces is removed to avoid problems such as poor appearance of the subsequent cell and poor passivation effect, and the silicon wafer is further cleaned and dried.

[0151] Deposition of AlO X : a tubular atomic layer deposition (ALD) device is used to deposit an AlO X film on the front surface of the silicon wafer with a thickness controlled at 5nm.

[0152] Deposition of silicon nitride on front and back: SiN films were deposited on the front and back of the silicon wafer by a tube PECVD device X thin film. The thickness of the front SiN X thin film was controlled at 90 nm; the thickness of the back SiN X thin film was controlled at 97 nm, and the deposition temperature was 400-450℃.

[0153] After the deposition of silicon nitride on the front and back, the obtained complete silicon wafer semi-product was sorted by photoluminescence (PL), and the silicon wafer with a PL gray value of 20000 was selected (the silicon wafer with consistent PL gray value has consistent theoretical electrical performance of the cell). Two groups of 220 pieces of complete silicon wafer semi-products after the deposition of silicon nitride on the front and back were formed by the sister wafer sorting method, and the following example and comparative example experiments were performed, respectively.

[0154] The small cell was prepared by the scheme of the application in the example

[0155] Step A) laser cutting: a group of 220 pieces of complete silicon wafer semi-products after the deposition of silicon nitride on the front and back were cut by laser cutting, and each complete silicon wafer was cut into two small silicon wafers, each small silicon wafer had one cutting surface, and the edge length of each small silicon wafer was 182 mm*91 mm.

[0156] Step B) deposition of aluminum oxide passivation film on the cutting surface using a chain atomic layer deposition device: a plurality of small silicon wafers were stacked in a carrier with only one side opening, the cutting surface was uniformly placed at the opening, and the remaining surfaces were closed to the carrier to prevent the deposition of aluminum oxide film on the cutting surface. The cutting surface side was placed in the reaction zone, and the stacked small silicon wafers were transported in the reaction zone by a transport belt. The exposed cutting surface side entered the reaction source zone of TMA and H2O in turn, and the number of TMA and H2O reaction source zones was 50 each. The transport belt speed was 1 cm / s, the nitrogen flow of the air curtain isolation zone was 1000 sccm, the process temperature was 200℃, TMA and H2O were carried by nitrogen, the carrying source nitrogen flow was 1500 sccm, and a 5 nm aluminum oxide passivation film layer was deposited to obtain a passivation film small silicon wafer.

[0157] The aluminum oxide thin film has good chemical passivation and field passivation functions, which can effectively reduce the surface defects of the cutting surface and reduce the carrier recombination center.

[0158] Step C) screen printing and sintering to form a small cell: metal paste was printed on the front and back of the passivation film small silicon wafer, and then high-temperature sintering was performed to form a metallized contact. Under the promotion of high-temperature sintering, H in the aluminum oxide passivation film of the cutting surface can diffuse to the cutting surface to saturate the dangling bonds on the cutting surface, and further improve the field passivation effect of the aluminum oxide thin film on the cutting surface.

[0159] The comparative example cuts the finished battery to form a small piece of battery with no passivation on the cutting surface

[0160] Step a) screen printing and sintering to form a whole piece of battery: another group of 220 pieces of front and back silicon nitride coated whole silicon wafer semi-finished products, the front and back surfaces are printed with metal paste and sintered to form metalized contacts to prepare a whole piece of battery.

[0161] Step b) laser cutting of the whole piece of battery to form a small piece of battery: the whole piece of battery is cut by laser cutting, each piece of battery is divided into two small pieces of battery, and the edge length of each small piece of battery is 182mm*91mm.

[0162] The small piece of battery prepared by the embodiment and the comparative example of the application is packaged into a photovoltaic module for performance testing.

[0163] The packaged module is tested for power, and the module packaged by the application is a conventional 72 version module, that is, a module is composed of 72 conventional whole piece of batteries, and the size of the whole piece of battery is 182mm*182mm. Since the battery piece is cut into two small pieces of battery in this embodiment, 144 small pieces of battery are required for the same module specification, and the size of the small piece of battery is 182mm*91mm, that is, a photovoltaic module packaged by 144 small pieces of battery.

[0164] Three pieces of the above photovoltaic module are formed by the embodiment and the comparative example, respectively, and the average electrical performance of each group of photovoltaic modules is shown in Table 1, which is the average electrical performance of each group of photovoltaic modules prepared by the embodiment and the comparative example of the application.

[0165] Table 1

[0166] As can be seen from Table 1, the power Pmax of the module of the embodiment using the scheme of the application is 4W higher than that of the comparative example, which reflects the effect of the scheme on improving the power of the packaged photovoltaic module through cutting surface passivation.

[0167] The application provides a preparation method for small piece of crystalline silicon battery with specific steps and specific equipment. Before screen printing, the whole silicon wafer semi-finished product is cut into multiple small pieces of silicon wafer using laser non-destructive cutting, and then a chain type passivation film deposition device is used simultaneously to form an integrated device before screen printing, so that the cut small piece of silicon wafer passes through the chain type edge passivation film deposition device to enter the screen printing and sintering to form a small piece of battery. The application particularly uses a chain type atomic layer deposition device (CALD) which can be seamlessly connected with the subsequent chain type screen printing step, and the annealing and activation of the passivation film passivation effect is carried out by using a sintering machine, so as to reduce the minority carrier recombination of the cutting surface, thereby improving the photoelectric conversion efficiency of the small piece of battery and the power of the packaged module.

[0168] The above has carried on the detailed introduction to the new method for improving the passivation performance of small piece battery and the integrated production system for silicon wafer passivation film deposition and silk screen printing provided by the present application, the principle and implementation mode of the present application are described by applying specific examples in this paper, the above embodiment description is only used to help understand the method and core idea of the present application, including the best mode, and also enable any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for ordinary skilled person in the art, some improvements and modifications can be made to the present application without departing from the principle of the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application. The scope of patent protection of the present application is limited by the claims, and can include other embodiments that can be thought by those skilled in the art. If these other embodiments have structural elements that are not different from the expression of the claims, or if they include equivalent structural elements that are not substantially different from the expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A process for the production of small-area photovoltaic cells, characterized in that, The method comprises the following steps: Step 1: providing a complete silicon wafer comprising a front surface and a back surface opposite to the front surface, and a side surface connecting the front surface and the back surface, and performing a photovoltaic cell production process on the complete silicon wafer to obtain a complete silicon wafer semi-product before screen printing; Step 2: cutting the complete silicon wafer semi-product to obtain a plurality of small silicon wafers; The side surface of the small silicon wafer has at least one cutting surface; Step 3: performing chain atomic layer deposition on the small silicon wafer to deposit a passivation film only on the cutting surface to obtain a passivation film small silicon wafer; Step 4: screen printing the passivation film small silicon wafer and then sintering to obtain a small photovoltaic cell.

2. The production process according to claim 1, characterized in that, The side length of the complete silicon wafer is 155-230 mm; The cutting method comprises laser cutting; The small silicon wafer has oppositely arranged short edge portions and long edge portions, and the side length of the short edge portion is 10-115 mm.

3. The production process according to claim 1, characterized in that, The preparation process of the complete silicon wafer semi-product further comprises texturing, diffusion, edge and back surface treatment, and front surface and / or back surface passivation.

4. The production process according to claim 1, characterized in that, The number of cutting surfaces of a single small silicon wafer is one or two.

5. The production process according to claim 1, characterized in that, In step 3, the small silicon wafer is placed in a single or multiple front and back surface stacking manner.

6. The production process according to claim 5, characterized in that, A plurality of small silicon wafers are stacked by a carrier.

7. The production process according to claim 1, characterized in that, The chain atomic layer deposition is performed by using a chain atomic layer deposition device, the non-cutting surface of the small silicon wafer is located in a gas curtain isolation zone formed by a protective gas, and the cutting surface is located in a passivation film reaction source deposition zone formed by a passivation film reaction source gas phase. The protective gas is a gas that does not participate in the passivation film deposition reaction and does not react with the small silicon wafer.

8. The production process according to claim 7, characterized in that, The flow rate of the passivation film reaction source gas phase is greater than or equal to the flow rate of the protective gas. The small silicon wafer is placed with the front surface and / or the back surface facing upward in the gas curtain isolation zone formed by the downward passage of the protective gas. The passivation film reaction source gas phase forms a passivation film reaction source deposition zone from top to bottom, and the cutting surface is located on one side of the passivation film reaction source deposition zone perpendicular to the flow direction of the passivation film reaction source gas phase. The gas curtain isolation zone is used to isolate the passivation film reaction source gas phase from the non-cutting surface of the small silicon wafer during the passivation film reaction source deposition process. The gas curtain isolation zone fills the entire chain atomic layer deposition chamber except the passivation film reaction source deposition zone.

9. The production process according to claim 1 or 7, characterized in that, The passivation film deposition is performed by alternating single or multiple cycles of the passivation film reaction source to form the passivation film. The alternating single deposition is performed by first depositing a first reaction source on the cutting surface in a passivation film first reaction source deposition zone, then entering a gas curtain isolation zone, and then sequentially entering a passivation film Nth reaction source deposition zone to deposit an Nth reaction source for reaction to form the passivation film; wherein N is greater than or equal to 2. The alternating multiple deposition is specifically that the cutting surface first enters a first reaction source deposition area of a passivation film to deposit a first reaction source, then enters a gas curtain isolation area, and then sequentially enters an Nth reaction source deposition area of the passivation film to deposit an Nth reaction source to react, to form a single-layer passivation film, and then enters the gas curtain isolation area, and then enters another first reaction source deposition area of the passivation film to repeat the above steps to form the passivation film; wherein N is greater than or equal to 2. The chain atomic layer deposition is specifically that the spaced single or multiple stacked small silicon pieces are transported through a conveying device to sequentially deposit the passivation film.

10. The production process according to claim 1 or 5, characterized in that, The screen printing includes chain screen printing. The chain atomic layer deposition and the chain screen printing are integrated into a continuous production process by conveying the passivation film small silicon pieces to a screen printing feeding position through a chain conveying device. The passivation film includes an aluminum oxide passivation film. The passivation film is a hydrogen-rich film, and the passivation film is passivated during the sintering process.

11. An integrated production system for silicon wafer passivation film deposition and screen printing, characterized in that, It comprises: a chain atomic layer deposition device and a screen printing device connected to the chain atomic layer deposition device; the chain atomic layer deposition device comprises a conveying device and an atomic layer deposition device; the atomic layer deposition device is provided with a gas curtain isolation area and a passivation film reaction source deposition area.

12. The integrated production system of claim 11, wherein, The screen printing device includes a chain screen printing device; The chain screen printing device includes a chain screen printing conveying device; The chain atomic layer deposition device is connected to the chain screen printing conveying device through the conveying device to form an integrated continuous production system of passivation film deposition and screen printing; The conveying device includes a conveying belt, an upper and lower feeding structure at both ends of the conveying belt, and a connection structure connected to the chain screen printing conveying device.

13. The integrated production system of claim 11, wherein, The gas curtain isolation area is perpendicular to the conveying belt of the conveying device; The passivation film reaction source deposition area is perpendicular to the conveying belt of the conveying device; A plurality of first spray holes and a plurality of second spray holes are provided on the chain atomic layer deposition device above the conveying belt; a plurality of gas outlet holes are provided on the chain atomic layer deposition device below the conveying belt; The first spray holes blow out passivation film reaction sources to form the passivation film reaction source deposition area, and the second spray holes blow out protective gas to form the gas curtain isolation area; The distance between the first spray holes and the silicon piece is less than or equal to the distance between the second spray holes and the silicon piece.

14. The integrated production system of claim 11, wherein, The passivation film reaction source deposition area includes a plurality of passivation film different reaction source deposition areas, or a plurality of passivation film same reaction source deposition areas and a plurality of passivation film different reaction source deposition areas; The gas curtain isolation area is arranged between the plurality of passivation film different reaction source deposition areas; The gas curtain isolation area is arranged between the plurality of passivation film same reaction source deposition areas.

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