Production process of small photovoltaic cell and integrated production system for silicon wafer passive film deposition and silk-screen printing

Abstract

The invention provides a production process of a small photovoltaic cell. The invention further provides an integrated production system for silicon wafer passive film deposition and silk-screen printing. Before silk-screen printing, a complete silicon wafer semi-finished product is cut into a plurality of small silicon wafers through laser nondestructive cutting, and then chain type passive film deposition equipment is used at the same time and installed before silk-screen printing to form integrated equipment. Performing silk-screen printing and sintering on the cut small silicon wafers through chain type edge passive film deposition equipment to form small batteries; according to the method, a chained atomic layer deposition (CALD) device is particularly adopted, seamless connection with a subsequent chained silk-screen printing step can be achieved, annealing is conducted through a sintering machine, the passivation effect of a passivation film is activated, the purpose of reducing recombination of minority carriers on a cutting face is achieved, and therefore the purpose of improving the photoelectric conversion efficiency of a small cell and the power of a packaged assembly is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic cell preparation, and in particular relates to a production process for small-piece photovoltaic cells and an integrated production system for silicon wafer passivation film deposition and screen printing. Background Art

[0002] In existing multi-slice modules, patchwork modules or shingled modules, the complete cell is generally cut into multiple small cells before packaging the module. The cut surface of the small cell after cutting is the bare silicon surface. The bare silicon surface has many defects and the surface charge recombination is very serious, which affects the photoelectric conversion efficiency of the small cell and further affects the power generation of the packaged photovoltaic module. Figure 1 , Figure 1 The present invention is a schematic diagram of the process flow of manufacturing and packaging small-piece batteries into photovoltaic modules in the prior art. For example, CN111430506A in the prior art discloses cutting on the finished battery and stacking the small-piece batteries together to passivate the cut surface. However, since the finished battery has surface electrodes, the electrode height affects the degree of closeness between the stacked sheets when stacked together, causing the passivation film to be deposited on the edge and also on the front or back of the battery, resulting in wrap-around plating. Wrap-around plating is the deposition of the passivation film on the non-coated surface. Since the passivation film is mostly an insulating film, when it covers the electrode surface, it will cause poor contact of the serial welding in the module packaging stage, that is, the phenomenon of cold welding, resulting in a decrease in the power generation of the module and extremely unstable reliability of the module. In order to activate the passivation effect of the passivation film, additional annealing equipment is required, and the high temperature and contact with air during the annealing process easily cause oxidation of the electrode, resulting in an increase in the cost of the small-piece battery and a decrease in the yield.

[0003] Although the prior art also involves cutting complete silicon wafers into small silicon wafers before or during battery manufacturing, and then processing the small silicon wafers to form small batteries, since the battery manufacturing process also requires multiple heat treatment processes, the heat treatment equipment is mostly tubular equipment. The existing equipment and carriers do not match the size of the small silicon wafers, which is bound to bring new problems such as increased costs or reduced production capacity.

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

[0005] In view of this, the technical problem to be solved by the present invention is to provide a production process for small-piece photovoltaic cells, in particular, a new method for improving the passivation performance of small-piece cells. The present invention cuts silicon wafers during the cell manufacturing process and passivates the surface defects by depositing a passivation film on the cut surface, thereby achieving the effect of improving the efficiency of the cut small-piece cells and the power of the packaged photovoltaic modules. The present invention does not pass through a tubular device after cutting, and the device for depositing the passivation film is a chain device, which is perfectly compatible with the existing back-end mass production process.

[0006] The present invention provides a production process for a small photovoltaic cell, comprising the following steps:

[0007] Step 1: providing a complete silicon wafer, wherein the complete silicon wafer comprises a front side, a back side opposite to the front side, and a side surface connecting the front side and the back side, and subjecting the complete silicon wafer to a photovoltaic cell production process 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 multiple small silicon wafers;

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

[0010] Step 3: performing chain atomic layer deposition on the small silicon wafer, and performing passivation film deposition only on the cut surface, to obtain a small silicon wafer with a passivation film;

[0011] Step 4: Screen-print the small silicon wafer with the passivation film, and then sinter it to obtain a small photovoltaic cell.

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

[0013] The cutting method includes laser cutting;

[0014] The small silicon wafer has a short side and a long side that are arranged opposite to each other, and the length of the short side is 10 to 115 mm.

[0015] Preferably, the preparation process of the complete silicon wafer semi-finished product also includes: texturing, diffusion, edge and back surface processing, and front and / or back surface passivation.

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

[0017] Preferably, in step 3, the small silicon wafers are placed in a single or multiple stacked manner with the front and back sides stacked.

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

[0019] Preferably, the chain atomic layer deposition is specifically to use a chain atomic layer device for deposition, wherein the non-cut surface of the small silicon wafer is placed in an air curtain isolation zone formed by a protective gas, and the cut surface is placed in a passivation film reaction source deposition zone formed by a passivation film reaction source gas phase, to perform the passivation film deposition;

[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 wafer.

[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] Specifically, the small silicon wafer is located with its front side and / or back side facing upwards in the gas curtain isolation zone formed by the protective gas flowing from top to bottom;

[0023] Specifically, the passivation film reaction source gas phase forms a passivation film reaction source deposition area from top to bottom, and the cutting surface is perpendicular to the flow direction of the passivation film reaction source gas phase and is placed on one side of the passivation film reaction source deposition area;

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

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

[0026] Preferably, the passivation film deposition is specifically a process of alternately depositing a passivation film reaction source once or multiple times in a cycle to form the passivation film;

[0027] The alternating single deposition is specifically that the cut surface first enters the first reaction source deposition area of ​​the passivation film to deposit the first reaction source, then enters the air curtain isolation area, and then sequentially enters the Nth reaction source deposition area of ​​the passivation film to deposit the Nth reaction source for reaction to form the passivation film; wherein N is greater than or equal to 2;

[0028] Specifically, the alternating multiple depositions are as follows: the cut surface first enters the first reaction source deposition area of ​​the passivation film to deposit the first reaction source, then enters the air curtain isolation area, and then sequentially enters the Nth reaction source deposition area of ​​the passivation film to deposit the Nth reaction source for reaction to form a single-layer passivation film, then enters the air curtain isolation area, and then enters another first reaction source deposition area of ​​the passivation film, and repeats 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 to transport the spaced single or multiple stacked small silicon wafers through a conveying device and sequentially perform 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 chain-transmitted to transport the small silicon wafer of the passivation film to the screen printing feeding place 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 during the sintering process, the passivation film will be passivated at the same time.

[0034] The present invention also provides an integrated production system for silicon wafer passivation film deposition and screen printing, comprising: a chain atomic layer deposition device and a screen printing device connected to the chain atomic layer deposition device;

[0035] The chain-type atomic layer deposition device comprises a transmission device and an atomic layer deposition device;

[0036] The atomic layer deposition device is provided with an air 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 to the chain screen printing conveying device through the transmission device to form an integrated continuous production system of passivation film deposition and screen printing;

[0040] The transmission device comprises a transmission belt, loading and unloading structures at both ends of the transmission belt, and a connection structure with the chain-type screen printing transmission device.

[0041] Preferably, the air curtain isolation zone is arranged perpendicular to the conveying belt of the conveying device;

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

[0043] The chain-type atomic layer deposition device above the conveyor belt is provided with a plurality of first spray holes and a plurality of second spray holes; the chain-type atomic layer deposition device below the conveyor belt is provided with a plurality of air outlet holes;

[0044] The first spray hole blows out the passivation film reaction source to form the passivation film reaction source deposition area, and the second spray hole blows out the protective gas to form the air 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 includes a plurality of passivation film deposition areas with different reaction sources, or a plurality of passivation film deposition areas with the same reaction source and a plurality of passivation film deposition areas with different reaction sources;

[0047] The air curtain isolation area is arranged between the plurality of passivation film deposition areas with different reaction sources;

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

[0049] The present invention provides a production process for small photovoltaic cells, comprising the following steps: Step 1: providing a complete silicon wafer, wherein the complete silicon wafer comprises a front side, a back side opposite to the front side, and a side surface connecting the front side and the back side, and subjecting the complete silicon wafer to a photovoltaic cell production process before screen printing to obtain a complete silicon wafer semi-finished product; Step 2: cutting the complete silicon wafer semi-finished product to obtain small silicon wafers; the side surface of the small silicon wafer has a single or two cutting surfaces; Step 3: subjecting the small silicon wafer to chain atomic layer deposition, and only performing passivation film deposition on the cutting surface to obtain a small silicon wafer with a passivation film; Step 4: screen printing the small silicon wafer with the passivation film, and then sintering to obtain a small photovoltaic cell. Compared with the prior art, the present invention provides a method for preparing a crystalline silicon small-chip battery with specific steps and in conjunction with specific equipment. Before screen printing, the present invention first uses laser non-destructive cutting to cut a whole silicon wafer into multiple small silicon wafers, and then uses a chain passivation film deposition device at the same time, which is installed before screen printing to form an integrated device, and the cut small silicon wafers are passed through the chain edge passivation film deposition device into screen printing and sintering to form small-chip batteries; the present invention particularly adopts a chain atomic layer deposition device (Chain Atomic Layer Deposition, referred to as CALD), which can be seamlessly connected with the subsequent chain screen printing steps, and uses a sintering machine to anneal and activate the passivation effect of the passivation film, so as to achieve the purpose of reducing the recombination of minority carriers on the cut surface, thereby achieving the purpose of improving the photoelectric conversion efficiency of the small-chip battery and the power of the packaged component.

[0050] In the photovoltaic cell manufacturing process, the present invention cuts and slices the silicon wafers before screen printing in the cell manufacturing process to form small silicon wafers, and deposits a passivation film on the cut surface of the small silicon wafer to passivate its defects, thereby achieving the effect of improving the photoelectric conversion efficiency of the formed small cell and improving the power generation of the packaged photovoltaic module. The solution of the present invention does not pass through a tubular device after cutting, and the device for depositing the passivation film is a chain device, which is perfectly consistent with the existing back-end mass production process. The present invention can be applied to a variety of crystalline silicon solar cells, not limited to PERC, TOPCon cells, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic diagram of the process flow of manufacturing and packaging small-chip cells into photovoltaic modules in the prior art;

[0052] Figure 2 A schematic diagram of the process flow provided by the present invention;

[0053] Figure 3 A schematic diagram of the structure of the chain passivation device provided by the present invention;

[0054] Figure 4 A schematic top view of the structure of the chain atomic layer deposition device provided by the present invention. DETAILED DESCRIPTION

[0055] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0056] All raw materials of the present invention have no particular limitation on their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art.

[0057] The raw materials used in the present invention have no particular limitation on their purity. In the present invention, the raw materials are preferably electronically pure or have conventional purity in the field of preparing small photovoltaic cells.

[0058] The brands and abbreviations of all materials of the present invention are conventional brands and abbreviations in the field. Each brand and abbreviation is clear and definite in the field of its related use. Those skilled in the art can purchase them from the market or prepare them by conventional methods based on the brands, abbreviations and corresponding uses.

[0059] The abbreviations of all processes of the present invention are conventional abbreviations in the field, and each abbreviation is clear and unambiguous in the field of its related use. Those skilled in the art can understand its conventional process steps based on the abbreviations.

[0060] The present invention provides a production process for a small photovoltaic cell, comprising the following steps:

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

[0062] Step 2: cutting the complete silicon wafer semi-finished product to obtain multiple 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, and performing passivation film deposition only on the cut surface, to obtain a small silicon wafer with a passivation film;

[0065] Step 4: Screen-print the small silicon wafer with the passivation film, and then sinter it to obtain a small photovoltaic cell.

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

[0067] In the present invention, the side length 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 invention, the cutting method preferably includes laser cutting.

[0069] In the present invention, the small silicon wafer has a short side and a long side that are arranged opposite to each other, and the length of the short side is preferably 10 to 115 mm, more preferably 30 to 100 mm, and more preferably 50 to 80 mm.

[0070] In the present invention, the preparation process of the complete silicon wafer semi-finished product preferably also includes: texturing, diffusion, edge and back processing, front and / or back passivation. Specifically, texturing is used to form a non-flat silicon wafer surface to enhance the light incident effect; diffusion is used to form a PN junction to produce photogenerated carriers under light; edge and back processing includes etching and alkaline polishing to remove the PN junction at the edge and back of the silicon wafer and form a relatively flat silicon wafer back structure; front and / or back passivation, corresponding to different structural batteries, the passivation process and film material are selected, such as depositing silicon nitride layers on the front and back, which is not limited here.

[0071] The present invention then uses chain atomic layer deposition on the small silicon wafer, and only deposits a passivation film on the cut surface to obtain a small silicon wafer with a passivation film.

[0072] In the present invention, the placement method of the small silicon wafers preferably includes a single or multiple front and back stacked placement, and more preferably multiple front and back stacked placement is achieved through a carrier. Specifically, multiple small silicon wafers can be placed in a carrier to achieve stacking. Furthermore, the carrier can be provided with an opening and a closed surface, and the cut surface is placed corresponding to the opening of the carrier, and the remaining non-coated surfaces are placed corresponding to the closed surfaces of the carrier to better reduce the plating around the non-coated surfaces; the carrier can also be a fixing device to fix the stacked silicon wafers, and the specific structure is not limited here.

[0073] In the present invention, the chain atomic layer deposition can specifically be performed by using a chain atomic layer device (chain atomic layer deposition apparatus) to perform deposition, wherein the non-cut surface of the small silicon wafer is located in an air curtain isolation area formed by a protective gas, while the cut surface is placed in a passivation film reaction source deposition area formed by a passivation film reaction source gas phase to perform the passivation film deposition.

[0074] In the present invention, the protective gas can be specifically a gas that does not participate in the passivation film deposition reaction and a gas that does not react with the small silicon wafer. At the same time, the protective gas does not react with common device materials such as metal and rubber.

[0075] In the present invention, the flow rate of the passive 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 invention, the located specifically may be that the front side and / or the back side of the small silicon wafer faces upwards and is located in the gas curtain isolation area formed by the protective gas passing from top to bottom.

[0077] In the present invention, the placing may specifically 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 placed 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 invention, the air curtain isolation zone is preferably used to isolate the passivation film reaction source during deposition, and the passivation film reaction source gas phase is preferably in contact with the non-cut surface of the small silicon wafer.

[0079] In the present invention, the air curtain isolation zone preferably fills the entire chain atomic layer deposition chamber except the passivation film reaction source deposition zone.

[0080] In the present invention, the passivation film deposition may specifically be a single or multiple cycle deposition of the passivation film reaction source to form the passivation film, more preferably a multiple cycle deposition of the passivation film reaction source to form the passivation film.

[0081] In the present invention, the alternating single deposition may specifically be that the cutting surface first enters the first reaction source deposition area of ​​the passivation film to deposit the first reaction source, then enters the air curtain isolation area, and then sequentially enters the Nth reaction source deposition area of ​​the passivation film 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 invention, the alternating multiple depositions are specifically that the cutting surface first enters the first reaction source deposition area of ​​the passivation film to deposit the first reaction source, then enters the air curtain isolation area, and then successively enters the Nth reaction source deposition area of ​​the passivation film to deposit the Nth reaction source for reaction to form a single-layer passivation film, then enters the air curtain isolation area, and then enters another passivation film first reaction source deposition area, and repeats the above steps to form the passivation film; wherein N is greater than or equal to 2.

[0083] In the present invention, the chain atomic layer deposition may specifically be to transport the spaced single or multiple stacked small silicon wafers through a conveying device and sequentially perform the passivation film deposition.

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

[0085] In the present invention, the passivation film is preferably a hydrogen-rich film, and during the sintering process, the passivation film is passivated at the same time.

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

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

[0088] In the present invention, the chain atomic layer deposition and the chain screen printing are preferably carried out by chain conveying, and the small silicon wafer of the passivation film is transported to the screen printing loading place for the screen printing, and the chain atomic layer deposition and the chain screen printing form an integrated continuous production process.

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

[0090] The chain-type atomic layer deposition device comprises a transmission device and an atomic layer deposition device;

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

[0092] In the present invention, the screen printing device preferably includes a chain screen printing device.

[0093] In the present invention, the chain screen printing device preferably includes a chain screen printing conveying device.

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

[0095] In the present invention, the transmission device preferably includes a transmission belt, loading and unloading structures at both ends of the transmission belt, and a connection structure with the chain-type screen printing transmission device.

[0096] In the present invention, the air curtain isolation zone is preferably arranged perpendicular to the conveying belt of the conveying device.

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

[0098] In the present invention, the chain-type atomic layer deposition device above the conveyor belt is preferably provided with a plurality of first spray holes and a plurality of second spray holes; the chain-type atomic layer deposition device below the conveyor belt is provided with a plurality of gas outlet holes. Specifically, the first spray hole includes an upper reaction source gas phase spray hole, and the second spray hole includes an upper air curtain spray hole.

[0099] In the present invention, the aperture of the upper air curtain spray hole is preferably 1-3 mm, more preferably 1.2-2.8 mm, more preferably 1.5-2.5 mm. The aperture of the upper reaction source gas phase spray hole is preferably 1-3 mm, more preferably 1.2-2.8 mm, more preferably 1.5-2.5 mm.

[0100] In the present invention, the density of the air curtain area of ​​the upper air curtain spray hole is 1 to 3 per cm 2 , more preferably 2 to 3 pieces / cm 2 The density of the reaction source area of ​​the upper reaction source gas phase spray hole is 1 to 3 per cm 2 , more preferably 2 to 3 pieces / cm 2 .

[0101] In the present invention, the aperture of the lower air outlet is preferably 4 to 5 cm, more preferably 4.2 to 4.8 cm, and more preferably 4.4 to 4.6 cm. The air outlet is relatively large, and the aperture density is not set.

[0102] In the present invention, the first spray hole blows out the passivation film reaction source to preferably form the passivation film reaction source deposition area.

[0103] In the present invention, the protective gas blown out from the second spray hole preferably forms the gas curtain isolation zone.

[0104] In the present invention, the distance between the first spray hole, i.e., the spray hole for 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 for blowing out the protective gas (upper air 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 to 20 mm, more preferably 8 to 18 mm, and more preferably 10 to 15 mm. That is, the distance between the spray hole of the passivation film reaction source and the silicon wafer is closer to reduce the influence of the protective gas on the reaction source gas phase.

[0105] In the present invention, the passivation film reaction source deposition area preferably includes a plurality of passivation film different reaction source deposition areas. Alternatively, in the present invention, 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 invention, the air curtain isolation zone is preferably provided between the plurality of passivation film deposition zones of different reaction sources.

[0107] In the present invention, the air curtain isolation zone is preferably provided between the plurality of passivation film deposition zones having the same reaction source.

[0108] Before screen printing, the present invention uses laser non-destructive cutting to cut the entire silicon wafer semi-finished product into multiple small silicon wafers, and at the same time uses a chain passivation film deposition device, which is installed before screen printing to form an integrated device, and the cut small silicon wafers are sequentially passed through the chain passivation film deposition device, screen printing equipment, and sintering equipment to form small batteries. In the present invention, the chain passivation film deposition device adopts a chain atomic layer deposition device. Furthermore, the cutting and slicing are carried out after the front and back silicon nitride films are plated and before screen printing, avoiding the need for heat treatment tubular equipment, and seamlessly connecting with the subsequent screen printing steps. The passivation effect of the passivation film on the cut surface is activated by sintering. The method of forming small batteries in this scheme can be perfectly combined with existing processes and equipment. The present invention also provides a structure of a chain atomic layer deposition device with a specific structure.

[0109] The present invention deposits a passivation film on the cut surface of a small silicon wafer by using a chain device that only deposits the edge cut surface. The chain device has a special structural design and can achieve the effect of only depositing the edge cut surface. At the same time, the chain device used for screen printing and sintering can be integrated together. At the same time, a sintering machine is used to perform annealing to activate the passivation effect of the passivation film, thereby achieving the purpose of reducing the recombination of minority carriers on the cut surface and improving the passivation effect, thereby achieving the purpose of improving the photoelectric conversion efficiency of the small battery and the power of the packaged component.

[0110] The present invention deposits a passivation film on the cut surface of the small silicon wafers after silicon nitride coating on the front and back sides and before screen printing through a chain atomic layer deposition device. At the same time, the same chain equipment as screen printing is used to integrate them together, and a sintering machine is used to perform annealing to activate the passivation effect of the passivation film, thereby achieving the purpose of reducing the recombination of minority carriers on the cut surface, that is, passivating the cut surface surface.

[0111] The present invention is to complete and refine the overall technical solution, better ensure the stability and continuity of the preparation process of small photovoltaic cells, and further improve the performance of the prepared small photovoltaic cells. The above-mentioned production process of small photovoltaic cells, that is, a new method for improving the passivation performance of small cells, and an integrated production system for silicon wafer passivation film deposition and screen printing can specifically include the following contents:

[0112] The present invention can be applied to a variety of crystalline silicon solar cells, not limited to PERC, TOPCon cells, etc. The present solution is introduced below using the currently mainstream TOPCon cell as an example.

[0113] Taking TOPCon cells as an example, the substrate is an n-type silicon wafer. The p+ doped layer is obtained by boron diffusion on the front side. A tunneling oxide layer and polysilicon are deposited on the back side. The n+ doped layer is obtained by in-situ phosphorus doping or intrinsic phosphorus diffusion. AlO is deposited on the front side. X The silicon nitride layer is deposited on the front and back sides; the corresponding metal electrode is obtained by screen printing and sintering. The general process includes: texturing, boron diffusion, etching, alkaline polishing, deposition of tunnel oxide layer and polysilicon, back phosphorus doping, annealing, RCA cleaning, front AlO X , deposit silicon nitride on the front and back, chain screen printing and sintering to form TOPCon cells.

[0114] The present invention is to deposit silicon nitride on the front and back sides, cut and slice the complete silicon wafer semi-finished product into small silicon wafers, and perform chain screen printing and sintering.

[0115] In the battery manufacturing process, after the silicon nitride layer on the front and back is made, a complete silicon wafer is cut into two or more small silicon wafers using laser cutting. The cut small silicon wafers are sequentially passed through chain atomic layer deposition equipment, chain screen printing and sintering to form small batteries. That is:

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

[0117] 2. Deposit a passivation film on the cut surface of a small silicon wafer. The small silicon wafer enters a passivation film deposition device that only deposits a fixed area of ​​the cut surface, and deposits a passivation film on the cut surface to form a small silicon wafer with a passivation film. Chain atomic layer deposition equipment is preferred, and the chain atomic layer deposition equipment and the screen sintering equipment form an integrated device;

[0118] 3. The small silicon wafer with passivation film enters the screen printing and sintering process to prepare the positive and negative electrodes. At the same time, the passivation film deposited on the edge can be annealed and activated during the high-temperature sintering process;

[0119] 4. Passivation film small silicon wafers form small batteries;

[0120] The small cell prepared by the solution of the present invention passivates the bare silicon surface of the cut surface, improves the photoelectric conversion efficiency of the small cell, and further improves the power generation power of the encapsulated photovoltaic module.

[0121] See also Figure 2 , Figure 2 The present invention provides a schematic diagram of the process flow.

[0122] The present invention deposits a passivation film on the cut edges of the cut small silicon wafers by using a chain device that only deposits the edge cut surfaces. The chain device has a special structural design and can achieve the effect of only depositing the cut surfaces. At the same time, the chain device used for screen printing and sintering can be integrated together. At the same time, a sintering machine is used to perform annealing to activate the passivation effect of the passivation film on the cut surfaces, thereby achieving the purpose of reducing the recombination of minority carriers on the cut surfaces and improving the passivation effect, thereby achieving the purpose of improving the photoelectric conversion efficiency of the battery and the power of the packaged components.

[0123] Specifically, in order to make silicon form good metallization contact with the metal electrode, the sintering furnace is usually set with a short high-temperature zone (such as a temperature zone of 700-850-650°C for 15 seconds). This short high-temperature zone can promote the H in the passivation film on the cut surface to diffuse to the cut surface through high temperature, saturate the dangling bonds on the cut surface, and further enhance the field passivation effect of the passivation film on the cut surface.

[0124] Specifically, the cut surface of the small silicon wafer after cutting is subjected to passivation film deposition by a chain atomic layer deposition device. The chain atomic layer deposition device is an integrated continuous production device integrated before the screen is loaded, that is, the process is loading → passivation film deposition → screen feeding. The chain atomic layer deposition device is Chain Atomic Layer Deposition (CALD for short) is a thin film deposition technology based on the principle of atomic layer deposition (ALD). However, compared with traditional ALD, CALD separates different source areas in chain space and produces different chemical reactions instead of separating them in time. CALD can be carried out under atmospheric pressure and can significantly increase the growth rate, which reaches multiple orders of magnitude of traditional ALD. When the present invention deposits a passivation film on the cut small silicon wafers by CALD, since the present invention only needs to deposit the passivation film on the cut surface, i.e., the cut edge, in order to avoid the passivation film being deposited on the non-cut side surface and the front and back surfaces of the small silicon wafers, the cut surface area is separated from the area that does not need to be coated in the CALD device design. Since the small silicon wafers need to move on the CALD, the present invention uses an air curtain to isolate them, i.e., the deposition area and the non-deposition area are in the same space, but the two areas are isolated by an air curtain. The air curtain can use gases including but not limited to inert gases such as nitrogen and helium that do not participate in the deposition reaction.

[0125] Specifically, the process and equipment for depositing the passivation film by chain atomic layer deposition (CALD) used in the present invention may specifically include the following contents:

[0126] The deposited passivation film includes but is not limited to aluminum oxide, silicon oxide, etc., which can passivate the bare silicon surface formed by cutting and reduce the film layer of carrier recombination centers.

[0127] Specifically, the present invention takes the passivation film as an aluminum oxide film layer as an embodiment, and the chain atomic layer deposition equipment shown in the present invention is mainly composed of a transmission part and a deposition part.

[0128] Specifically, the transmission part consists of a conveyor belt, which can be a metal guide rail, a belt, etc., as well as loading and unloading structures at both ends of the conveyor belt, and a connection structure with the screen printing equipment. It is used to transport single small silicon wafers or stacked silicon wafers after cutting, etc. The conveyor belt speed can be set according to specific needs. There is no restriction here. The specific transmission speed can be 0.01~1m / min; the deposition part is divided into an air curtain isolation area and a passivation film reaction source deposition area. The air curtain is generally an inert gas, including but not limited to nitrogen, helium, etc., 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 to avoid the occurrence of winding.

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

[0130] Specifically, the present invention uses TMA and H2O as reactants for deposition, and the small areas for passivation film deposition are TMA and H2O in sequence, that is, multiple small areas such as TMA-H2O-TMA-H2O, and the rest are air curtain isolation areas. The function of the air curtain isolation area is not only to isolate the two reaction sources to prevent them from contacting, but also the air curtain isolation area can isolate the coating area from the non-coating area, so that they are completely isolated, so as to achieve 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 invention is described in the manner of nitrogen carrying TMA and H2O source. The specific steps are that the conveyor carries the small silicon wafer after cutting. When passing through the TMA area, TMA is chemically adsorbed on the cut surface. The factors affecting this step are the flow rate of nitrogen carrying TMA source and the conveyor belt speed. The flow rate of nitrogen carrying source is in the range of 0-10000sccm, and the conveyor belt speed is 0.01-1m / min. After passing through the TMA area, the conveyor belt continues to carry the small silicon wafer forward and enters the H2O area. There is an air curtain isolation area between the TMA reaction source area and the H2O reaction source area, which can isolate TMA and H2O from reacting directly during transportation. This step is affected by the flow rate of nitrogen carrying H2O source and the transmission speed. The flow rate range is 0-10000sccm, and the transmission belt speed is 0.01-1m / min. This is a layer of aluminum oxide deposition, and subsequent cyclic deposition is carried out in this area with the transportation of the conveyor belt; the number of cycles is 1-1000 times, which can be set according to needs and is not limited here. The size of each TMA reaction source area and H2O reaction source area in the conveyor belt forward direction is 5 to 210 mm, and the size in the direction perpendicular to the conveyor belt is 5 to 20 mm. This area size can be set by the relevant reaction source design area.

[0132] Specifically, when the deposited passivation film is silicon oxide, the deposition logic is the same as above, TMA is replaced by an organic silicon source (such as silane), and H2O is replaced by remote plasma oxygen formed by an ozone generator, that is, the type of deposited passivation film can be quickly switched by changing the type of reactants in the deposition coating area.

[0133] Specifically, the passivation film is a H-rich film, and the H in the passivation film can diffuse to the cut surface at a high temperature during the sintering process, further enhancing the passivation effect of the passivation film.

[0134] In the present invention, the cutting surface is designed with a chain atomic layer deposition device to separate the air curtain isolation zone and the reaction zone, so that the passivation film is deposited only on the edge cutting surface. At the same time, the chain equipment used for screen printing and sintering can be integrated together, and the sintering machine is used to perform annealing to activate the passivation effect of the passivation film, so as to reduce the recombination of minority carriers on the cutting surface and improve the passivation effect, thereby achieving the purpose of improving the photoelectric conversion efficiency of small-chip batteries and the power of packaged components.

[0135] The present invention provides a method for preparing a crystalline silicon small-chip battery with specific steps and in combination with specific equipment. After the front and back silicon nitride films are deposited, that is, before screen printing, the present invention first uses laser non-destructive cutting to cut a complete silicon wafer semi-finished product into multiple small silicon wafers, and then simultaneously uses a chain passivation film deposition device, which is installed before screen printing to form an integrated device, and the cut small silicon wafers are passed through the chain edge passivation film deposition device into screen printing and sintering to form small-chip batteries; the present invention particularly adopts a chain atomic layer deposition device (CALD), which can be seamlessly connected with the subsequent chain screen printing step, and uses a sintering machine to perform annealing and activate the passivation effect of the passivation film, so as to achieve the purpose of reducing the recombination of minority carriers on the cut surface, thereby achieving the purpose of improving the photoelectric conversion efficiency of the small-chip battery and the power of the packaged component.

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

[0137] The structure of the chain passivation device (chain atomic layer deposition) provided by the present invention is introduced in Figure 3 . Figure 3 The present invention provides a schematic structural diagram of the chain-type passivation equipment.

[0138] Figure 3 In the schematic diagram of the passivation film deposition equipment, after cutting, a single small silicon wafer or multiple small silicon wafers are stacked in a carrier or fixture and transported on a conveyor belt, and the silicon wafer area to be coated (i.e., the cut surface) is exposed in the chamber coating area. The diagram shows only one cut surface, but there may be two cut surfaces in reality, i.e. Figure 3 The side opposite to the marked cutting surface is also the cutting surface side.

[0139] See also Figure 4 , Figure 4 A schematic top view of the structure of the chain atomic layer deposition device provided by the present invention. Figure 4In the detailed schematic diagram of the chain atomic layer deposition device, the position corresponding to the reaction source TMA\H2O is the cutting surface side of the small silicon wafer, and the figure is a single-sided cutting schematic diagram.

[0140] like Figure 4 As shown in the top view, the points in the schematic diagram represent spray holes, and the gas in the corresponding area can be blown out from the spray holes. 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 an air curtain isolation zone and a reaction source zone. The reaction source zone is further divided into a TMA zone and an H2O zone. The air curtain isolation zone fills the entire chamber except the reaction source zone. Generally, an inert gas is used to form the air curtain isolation zone. The present invention uses N2 with a purity of 99.9999%. The purpose of the air curtain isolation zone filling the entire chamber is to completely isolate the chamber from the outside world, and to fix the reaction source zone in the corresponding area on the advancing direction of the cutting surface to form a cutting surface reaction zone, and to completely isolate the cutting surface reaction zone from the area where no coating is required, so as to achieve the purpose of directional deposition of a passivation film.

[0141] The above content of the present invention provides a new method for improving the passivation performance of small-chip batteries and an integrated production system for silicon wafer passivation film deposition and screen printing. The present invention uses a chain atomic layer deposition device, i.e., a CALD device, which only deposits the edge cutting surface, to deposit the passivation film in a directional manner on the cut surface of the small silicon wafer after cutting. The advantage is that the specified side deposition can be achieved. At the same time, screen printing and sintering are both chain devices, which can be integrated together. The sintering machine is used for annealing and activation of the passivation film passivation effect, so as to achieve the purpose of reducing the recombination of minority carriers on the cut surface, thereby achieving the purpose of improving the photoelectric conversion efficiency of the small-chip battery and the power of the packaged component. Moreover, the method of forming the small-chip battery of the present invention can be perfectly combined with the existing processes and equipment. It has advantages over other small-chip battery formation or passivation methods.

[0142] The present invention adopts CALD equipment through a unique design of air curtain isolation area and reaction source area, fixes the reaction source area in a specific area in the forward direction during transportation, so as to achieve the purpose of depositing only the cut surface, and at the same time, through the design of air curtain isolation area except the reaction source area, the purpose of isolating different reaction source areas and isolating the coating area and non-coating area of ​​the cut surface is achieved. In the photovoltaic cell manufacturing link, the present invention cuts and slices the silicon wafers before screen printing in the cell manufacturing process to form small silicon wafers, and deposits a passivation film on the cut surface of the small silicon wafer to passivate its defects, thereby achieving the effect of improving the efficiency of the cut small cell and improving the power of the packaged photovoltaic module. The solution of the present invention does not pass through the tubular equipment after cutting, and the equipment for depositing the passivation film is a chain equipment, which perfectly matches the existing back-end mass production process.

[0143] In order to further illustrate the present invention, a production process of a small photovoltaic cell provided by the present invention and an integrated production system for silicon wafer passivation film deposition and screen printing are described in detail below in combination with embodiments. However, it should be understood that these embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are given only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention. The protection scope of the present invention is not limited to the following embodiments.

[0144] Taking TOPCon cells as an example, in the manufacturing process of TOPCon cells, after the silicon nitride is deposited on the front and back sides through the conventional production process, it is sequentially processed through texturing, boron diffusion, etching, alkaline polishing, deposition of tunnel oxide layer and phosphorus-doped polysilicon layer, RCA cleaning, front AlO X , the process of depositing silicon nitride on the front and back sides, the process and implementation methods of each process are as follows:

[0145] Texturing: In a trough texturing device, an alkaline solution is used to texturize n-type silicon wafers with a size of 182mm*182mm to form a pyramid-shaped texture surface to enhance the light incidence effect.

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

[0147] Etching: The back side of the silicon wafer after boron diffusion is etched on a single side in a chain cleaning machine to remove the borosilicate glass layer on the back side.

[0148] Alkali polishing: Use alkaline solution to treat the back of the silicon wafer to form a flatter back structure of the silicon wafer.

[0149] Deposition of tunneling oxide layer and phosphorus-doped polysilicon layer: Tubular PECVD is used to deposit tunneling oxide layer & doped amorphous silicon film & silicon oxide mask on the back of the silicon wafer, and then enters the annealing step, placing the silicon wafer in a quartz tube, 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: remove the phosphosilicate glass formed on the front and sides of the silicon wafer, remove the excess polysilicon plating on the front and sides to avoid subsequent problems such as poor battery appearance and poor passivation effect, and further clean and dry the silicon wafer.

[0151] Positive AlO X :Use tubular atomic layer deposition (ALD) equipment to deposit AlO on the front side of the silicon wafer X Thin film, thickness controlled at 5nm.

[0152] Silicon nitride is deposited on the front and back sides of the silicon wafer using a tubular PECVD device. X Thin film. Among them, the front SiN X The thickness of the film is controlled at 90nm; the back SiN X The thickness of the film is controlled at 97nm and the deposition temperature is 400-450℃.

[0153] After silicon nitride coating on the front and back sides, the obtained complete silicon wafer semi-finished products are sorted by photoluminescence (PL), and silicon wafers with a PL grayscale value of 20000 are selected (silicon wafers with consistent PL grayscale values ​​have consistent theoretical battery electrical performance). Two groups of 220 complete silicon wafer semi-finished products after silicon nitride coating on the front and back sides are formed by sister wafer sorting, and the following examples and comparative experiments are carried out respectively.

[0154] Example: Preparation of small battery using the scheme of the present invention

[0155] Step A) laser cutting: a group of 220 semi-finished silicon wafers with silicon nitride coating on the front and back sides are cut by laser, and each of the complete silicon wafers is cut into two small silicon wafers, each of which has a cutting surface, and the side length of each small silicon wafer is 182 mm*91 mm;

[0156] Step B) using a chain atomic layer deposition device to deposit an aluminum oxide passivation film on the cut surface: stack multiple small silicon wafers in a carrier with only one side opening, the cut surface is uniformly placed at the opening, and the other surfaces correspond to the closed surface of the carrier to prevent the deposition of aluminum oxide film except the cut surface, and the cut surface side is placed in the reaction zone, and the stacked small silicon wafers are transported and moved in the reaction zone by a conveyor belt, and the exposed cut surface side sequentially enters the reaction source area formed by TMA and H2O, and the number of TMA and H2O reaction source areas is 50 each. The conveyor belt speed is 1cm / s, the nitrogen flow rate in the air curtain isolation zone is 1000sccm, the process temperature is 200°C, TMA and H2O are carried by nitrogen, and the source nitrogen flow rate is 1500sccm, and a 5nm aluminum oxide passivation film layer is deposited to obtain a small silicon wafer with a passivation film.

[0157] Aluminum oxide film has good chemical passivation and field passivation functions, which can effectively reduce surface defects of the cut surface and reduce carrier recombination centers.

[0158] Step C) Screen printing and sintering to form a small cell: Metal paste is printed on the front and back of the small silicon wafer with the passivation film, and then sintered at high temperature to form a metallized contact. Under the promotion of high temperature of sintering, the H in the aluminum oxide passivation film on the cut surface can diffuse to the cut surface, saturating the dangling bonds on the cut surface, further enhancing the field passivation effect of the aluminum oxide film on the cut surface.

[0159] Comparative Example: Cutting finished batteries to form small pieces of batteries without passivation on the cut surface

[0160] Step a) Screen printing and sintering to form a whole cell: Another group of 220 complete silicon wafer semi-finished products with silicon nitride coating on both sides are printed with metal paste on the front and back sides and sintered to form metallized contacts to prepare a whole cell.

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

[0162] The performance of photovoltaic modules prepared in the embodiments of the present invention and the comparative examples was tested.

[0163] The packaged components are subjected to power testing. The packaged components of the present invention are conventional 72-format components, that is, one component is composed of 72 conventional whole-piece batteries, and the size of the whole battery is 182mm*182mm. Since the battery sheet is cut into two small-piece batteries in this embodiment, 144 small-piece batteries are required for the same component specifications, and the size of the small-piece batteries is 182mm*91mm, that is, a photovoltaic component is packaged by 144 small-piece batteries.

[0164] The present embodiment and the comparative example each formed three of the above photovoltaic modules. The average electrical performance of each group of photovoltaic modules is shown in Table 1. Table 1 shows the average electrical performance of each group of photovoltaic modules prepared in the present embodiment and the comparative example.

[0165] Table 1

[0166] Example Comparative Example Pmax / W 584.59 580.36 Voc / V 53.1 52.99 FF / % 81.07 80.71 Isc / A 13.58 13.57

[0167] It can be seen from Table 1 that the module power Pmax of the embodiment using the solution of the present invention is 4W higher than that of the control example, which reflects the effect of the solution on improving the power of the packaged photovoltaic module through the passivation of the cutting surface.

[0168] The present invention provides a method for preparing a crystalline silicon small-chip battery with specific steps and in combination with specific equipment. Before screen printing, the present invention first uses laser non-destructive cutting to cut a complete silicon wafer semi-finished product into multiple small silicon wafers, and then uses a chain passivation film deposition device at the same time, which is installed before screen printing to form an integrated device, and the cut small silicon wafers are passed through the chain edge passivation film deposition device into screen printing and sintering to form small-chip batteries; the present invention particularly adopts a chain atomic layer deposition device (CALD), which can be seamlessly connected with the subsequent chain screen printing steps, and uses a sintering machine to perform annealing and activate the passivation effect of the passivation film, so as to achieve the purpose of reducing the recombination of minority carriers on the cutting surface, thereby achieving the purpose of improving the photoelectric conversion efficiency of the small-chip battery and the power of the packaged component.

[0169] The above is a detailed introduction to a new method for improving the passivation performance of a small cell provided by the present invention and an integrated production system for silicon wafer passivation film deposition and screen printing. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and its core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the text of the claims, or if they include equivalent structural elements that are not substantially different from the text of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A production process for a small photovoltaic cell, characterized in that: The following steps are involved: Step 1: providing a complete silicon wafer, wherein the complete silicon wafer comprises a front side, a back side opposite to the front side, and a side surface connecting the front side and the back side, and subjecting the complete silicon wafer to a photovoltaic cell production process before screen printing to obtain a complete silicon wafer semi-finished product; Step 2: cutting the complete silicon wafer semi-finished product to obtain multiple 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, and performing passivation film deposition only on the cut surface, to obtain a small silicon wafer with a passivation film; Step 4: Screen-print the small silicon wafer with the passivation film, and then sinter it 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 to 230 mm; The cutting method includes laser cutting; The small silicon wafer has a short side and a long side that are arranged opposite to each other, and the length of the short side is 10 to 115 mm.

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

4. The production process according to claim 1, characterized in that: The number of the 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 wafers are placed in a single or multiple stacked manner on the front and back sides.

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

7. The production process according to claim 1, characterized in that: Specifically, the chain atomic layer deposition is to use a chain atomic layer device for deposition, wherein the non-cut surface of the small silicon wafer is placed in an air curtain isolation zone formed by a protective gas, and the cut surface is placed in a passivation film reaction source deposition zone formed by a passivation film reaction source gas phase, to perform the passivation film deposition; 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 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; Specifically, the small silicon wafer is located with its front side and / or back side facing upwards in the gas curtain isolation zone formed by the protective gas flowing from top to bottom; Specifically, the passivation film reaction source gas phase forms a passivation film reaction source deposition area from top to bottom, and the cutting surface is perpendicular to the flow direction of the passivation film reaction source gas phase and is placed on one side of the passivation film reaction source deposition area; The air curtain isolation zone is used to isolate the gas phase of the passivation film reaction source from contacting the non-cut surface of the small silicon wafer during the deposition process of the passivation film reaction source; The air curtain isolation area fills the entire chain atomic layer deposition chamber except the passivation film reaction source deposition area.

9. The production process according to claim 1 or 7, characterized in that: The passivation film deposition is specifically to deposit the passivation film reaction source alternately once or multiple times in a cycle to form the passivation film; The alternating single deposition is specifically that the cut surface first enters the first reaction source deposition area of ​​the passivation film to deposit the first reaction source, then enters the air curtain isolation area, and then sequentially enters the Nth reaction source deposition area of ​​the passivation film to deposit the Nth reaction source for reaction to form the passivation film; wherein N is greater than or equal to 2; Specifically, the alternating multiple depositions are as follows: the cut surface first enters the first reaction source deposition area of ​​the passivation film to deposit the first reaction source, then enters the air curtain isolation area, and then sequentially enters the Nth reaction source deposition area of ​​the passivation film to deposit the Nth reaction source for reaction to form a single-layer passivation film, then enters the air curtain isolation area, and then enters another first reaction source deposition area of ​​the passivation film, and repeats the above steps to form the passivation film; wherein N is greater than or equal to 2; The chain atomic layer deposition is specifically to transport the spaced single or multiple stacked small silicon wafers through a conveying device and sequentially perform the passivation film deposition.

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 chain-transmitted to transport the small silicon wafer of the passivation film to the screen printing feeding place for the screen printing, and the chain atomic layer deposition and the chain screen printing form an integrated continuous production process; The passivation film comprises an aluminum oxide passivation film; The passivation film is a hydrogen-rich film, and during the sintering process, the passivation film will be passivated at the same time.

11. An integrated production system for silicon wafer passivation film deposition and screen printing, characterized in that: include: A chain-type atomic layer deposition device and a screen printing device connected to the chain-type atomic layer deposition device; The chain-type atomic layer deposition device comprises a transmission device and an atomic layer deposition device; The atomic layer deposition device is provided with an air curtain isolation area and a passivation film reaction source deposition area.

12. The integrated production system according to claim 11, characterized in that: The screen printing device comprises a chain screen printing device; The chain screen printing device comprises a chain screen printing conveying device; The chain atomic layer deposition device is connected to the chain screen printing conveying device through the transmission device to form an integrated continuous production system of passivation film deposition and screen printing; The transmission device comprises a transmission belt, loading and unloading structures at both ends of the transmission belt, and a connection structure with the chain-type screen printing transmission device.

13. The integrated production system according to claim 11, characterized in that: The air curtain isolation zone is arranged perpendicular to the conveying belt of the conveying device; The passivation film reaction source deposition area is arranged perpendicular to the conveying belt of the conveying device; The chain-type atomic layer deposition device above the conveyor belt is provided with a plurality of first spray holes and a plurality of second spray holes; the chain-type atomic layer deposition device below the conveyor belt is provided with a plurality of air outlet holes; The first spray hole blows out the passivation film reaction source to form the passivation film reaction source deposition area, and the second spray hole blows out the protective gas to form the air curtain isolation area; 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.

14. The integrated production system according to claim 11, characterized in that: The passivation film reaction source deposition area includes a plurality of passivation film deposition areas with different reaction sources, or a plurality of passivation film deposition areas with the same reaction source and a plurality of passivation film deposition areas with different reaction sources; The air curtain isolation area is arranged between the plurality of passivation film deposition areas with different reaction sources; The air curtain isolation area is arranged between the plurality of passivation film deposition areas with the same reaction source.

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