Method for reducing warping degree in battery piece etching process, preparation method of TBC battery piece, TBC battery piece and wet chain type machine

Abstract

The invention relates to a method for reducing warping degree in a battery piece etching process, a preparation method of a TBC battery piece, the TBC battery piece and a wet chain type machine. The method for reducing the warping degree comprises the steps of obtaining a battery piece precursor; the first sensor generates a sensing signal after sensing that the battery piece precursor reaches a target position, and the industrial personal computer receives the sensing signal and starts the emitter; the light emitted by the emitter is reflected to the receiver by the battery piece precursor, the industrial personal computer calculates the warping degree of the battery piece precursor according to the running time of the light, and then calculates the spraying flow speed after the spraying piece is adjusted and the running speed after the conveying piece is adjusted according to the warping degree; the battery piece precursor penetrates through the area where the spraying piece is located at the running speed, and the spraying piece sprays cleaning liquid to the backlight face of the battery piece precursor at the spraying flow speed so that the backlight face of the battery piece precursor can be covered with a liquid film. And the etching unit performs wet etching on the light-facing surface of the battery piece precursor so as to improve the cleaning effect of the battery piece and reduce the warping degree of the battery piece.

Description

Technical Field

[0001] The present application relates to the technical field of solar cell wafers, and particularly to a method for reducing the warpage degree during the etching process of cell wafers, a preparation method of TBC cell wafers, a TBC cell wafer, and a wet bench. Background Art

[0002] Photovoltaic technology is a technology that directly converts solar energy into electrical energy using solar cell wafers. During the preparation process of solar cell wafers, low-pressure chemical vapor deposition (LPCVD), physical vapor deposition (PVD), atomic layer deposition (ALD), etc. are all common processes for depositing various material layers on the semiconductor surface, while boron diffusion and phosphorus diffusion are common process means for changing the electrical properties of semiconductors by doping impurity atoms inside the semiconductors. With the growing demand for industrial mass production of solar cell wafers, during the preparation process of TBC cell wafers, the insertion method used in high-temperature processes such as LPCVD, boron diffusion, and phosphorus diffusion has gradually replaced the single-insert method with the double-insert method. However, the double-insert method will cause the semi-finished cell wafers after high temperature to warp in different degrees and directions. At the same time, the double-insert method also requires the use of a wet bench etching process to solve the problem of overplating generated on the semiconductor surface during the deposition process and the doping process.

[0003] During the process of removing overplating by etching using a traditional wet bench, the overplated phosphosilicate glass layer is first removed by chain etching, and then the cell wafer precursor is directly sent to tank etching to clean the outer diffusion layer of phosphorus diffusion and the polysilicon overplating layer, and finally the borosilicate glass layer on the light-facing surface is removed. However, this method of removing overplating cannot be automatically adjusted according to the different warpage degrees of the cell wafer precursors, which will cause problems such as incomplete overplating removal, uneven etching, and even unclean cleaning of the cell wafer precursors, resulting in the appearance of recombination centers on the light-facing surface of the cell wafer precursors, leading to a leakage risk in the finished TBC cell wafers, thereby restricting the mass production and further development of TBC cell wafers. Summary of the Invention

[0004] Based on this, it is necessary to provide a method for reducing the warpage degree during the etching process of cell wafers, a preparation method of TBC cell wafers, a TBC cell wafer, and a wet bench that can automatically adjust the liquid film amount of the cleaning solution according to the warpage degree of the cell wafers.

[0005] A method for reducing the warpage degree during the etching process of cell wafers is applicable to a wet bench. Along the transportation direction of the cell wafer precursor, the wet bench includes a warpage degree detection unit, a spraying unit, and an etching unit arranged in sequence; the warpage degree detection unit includes an industrial control computer and a first sensor, a transmitter, and a receiver communicatively connected to the industrial control computer; the spraying unit includes a spraying member and a conveying member for conveying the cell wafer precursor, and the conveying member is arranged below the spraying member.

[0006] The method includes:

[0007] Obtaining a battery precursor, where the battery precursor includes a silicon wafer and a tunneling oxide layer, a doped polysilicon layer, and a phosphosilicate glass layer that are sequentially stacked on the silicon wafer;

[0008] After the first inductor senses that the battery precursor reaches the target position, an induction signal is generated, and the industrial control computer receives the induction signal and starts the transmitter;

[0009] The light emitted by the transmitter is reflected by the backlight surface of the battery precursor to the receiver, and the industrial control computer calculates the warpage of the battery precursor based on the running time of the light;

[0010] The industrial control computer calculates the adjusted spray flow rate of the spray member and the adjusted running speed of the conveying member according to the warpage;

[0011] The battery precursor passes through the area where the spray member is located at the running speed, and the spray member sprays cleaning liquid onto the backlight surface of the battery precursor at the spray flow rate, so that a liquid film covers the backlight surface of the battery precursor, and the etching unit performs wet etching on the light-facing surface of the battery precursor.

[0012] In one embodiment, the adjusted running speed of the conveying member is defined as v, and the expression of v is as follows:

[0013] ;

[0014] Wherein, v0 represents the initial running speed of the conveying member, α represents the proportional coefficient of the conveying member speed, δ represents the warpage of the battery precursor, L cell represents the length of the battery precursor, L film represents the diffusion length of the cleaning liquid on the battery precursor, and L film ≥L cell .

[0015] In one embodiment, the adjusted spray flow rate of the spray member is defined as Q, and the expression of Q is as follows:

[0016] ;

[0017] Wherein, Q0 represents the initial spray flow rate of the spray member, and β represents the proportional coefficient of the spray flow rate of the spray member.

[0018] In one embodiment, the spraying unit further includes a second sensor. After the industrial control computer calculates the adjusted spraying flow rate of the spraying member and the adjusted running speed of the conveying member, when the second sensor detects that the battery precursor enters the spraying unit and after a delay time t delay has passed, the spraying member starts to spray the cleaning liquid towards the battery precursor.

[0019] In one embodiment, the delay time t delay has the following expression: ;

[0020] wherein, the position where the battery precursor just enters the spraying unit is defined as the first position, D senor represents the distance between the first position and the spraying member in the moving direction of the battery precursor, and v0 represents the initial running speed of the conveying member.

[0021] In one embodiment, the method further includes: the spraying member stops spraying the cleaning liquid towards the battery precursor after a time T, and the time T satisfies the following relational expression:

[0022] ;

[0023] wherein, L cell represents the length of the battery precursor, and L nozzle represents the coverage length of the liquid spraying amount of the spraying member per unit time, and v represents the adjusted running speed of the conveying member.

[0024] In one embodiment, the tunneling oxide layer includes a first tunneling oxide layer and a second tunneling oxide layer, the doped polysilicon layer includes a boron-doped polysilicon layer and a phosphorus-doped polysilicon layer, and the method for obtaining the battery precursor includes:

[0025] Performing first double-sided polishing on the silicon wafer;

[0026] Successively forming the first tunneling oxide layer and the boron-doped polysilicon layer on both sides of the silicon wafer;

[0027] Performing first laser patterning on the backlight side of the silicon wafer to remove the borosilicate glass layer in the N region and the isolation region;

[0028] Performing second double-sided polishing on the silicon wafer to remove the first tunneling oxide layer and the boron-doped polysilicon layer in the N region and the isolation region;

[0029] Successively forming the second tunneling oxide layer and the phosphorus-doped polysilicon layer on both sides of the silicon wafer;

[0030] Perform a second laser patterning on the backlight side of the silicon wafer to remove the phosphosilicate glass layers in the P region and the isolation region, thereby obtaining the cell wafer precursor.

[0031] This application also provides a method for manufacturing a TBC cell wafer. The method uses the method for reducing the warpage degree during the etching process of the cell wafer described in any of the above embodiments. By wet etching, all layers on the light-facing side of the cell wafer precursor are removed to obtain a cell wafer intermediate; and

[0032] Perform double-sided texturing on the cell wafer intermediate. Etch the P region on the backlight side to the boron-doped polysilicon layer, the N region to the phosphorus-doped polysilicon layer, and the isolation region to the silicon wafer, and form a textured surface on the isolation region of the backlight side of the silicon wafer and the light-facing side of the silicon wafer;

[0033] Deposit a passivation layer and an antireflection layer on both sides of the cell wafer intermediate;

[0034] Prepare a positive electrode on the P region on the back of the cell wafer intermediate and a negative electrode on the N region to obtain a TBC cell wafer.

[0035] This application also provides a TBC cell wafer manufactured by the method for manufacturing a TBC cell wafer in the above embodiments.

[0036] This application also provides a wet bench for implementing the method for reducing the warpage degree during the etching process of the cell wafer described in any of the above embodiments. Along the transportation direction of the cell wafer precursor, the wet bench includes a warpage degree detection unit, a spraying unit, and an etching unit arranged in sequence;

[0037] The warpage degree detection unit includes a first sensor, a transmitter, a receiver, and an industrial control computer. The first sensor, the transmitter, and the receiver are all communicatively connected to the industrial control computer. Among them, the first sensor is configured to sense whether the cell wafer precursor reaches the target position and generate a sensing signal. The transmitter is configured to emit light towards the cell wafer precursor. The receiver is configured to receive the light reflected from the backlight side of the cell wafer precursor. The industrial control computer is configured to receive the sensing signal and start the transmitter, calculate the warpage degree of the cell wafer precursor based on the running time of the light, calculate the adjusted spraying flow rate of the spraying part and the adjusted running speed of the conveying part, and adjust the spraying flow rate of the spraying part and the running speed of the conveying part;

[0038] The spraying unit includes a spraying part and a conveying part for transporting the cell wafer precursor. The conveying part is arranged below the spraying part. The spraying part is configured to spray a cleaning liquid onto the backlight side of the cell wafer precursor;

[0039] The etching unit is configured to perform wet etching on the light-facing side of the cell wafer precursor.

[0040] Compared with the prior art, the method for reducing the warpage degree in the etching process of the battery wafer provided by the present application detects and calculates the warpage degree of the battery wafer precursor, and automatically and specifically adjusts the spraying flow rate of the spraying member in the spraying device and the running speed of the conveying member for transporting the battery wafer precursor in the spraying unit according to the obtained warpage degree. It can adjust the surface tension of the battery wafer precursor by accurately adjusting the amount of liquid film covering the battery wafer precursor, so that the etching solution used in the wet etching process uniformly covers the light-facing surface of the battery wafer precursor, enabling the etching reaction to proceed synchronously, reducing the stress gradient, and avoiding the phenomenon of uneven local etching of the battery wafer precursor in the wet etching. Thus, the battery wafer precursor can be accurately cleaned, improving the phenomenon of poor uniformity, over-etching, or residual oxide layer on the battery wafer after etching and cleaning, and further ensuring the stability and controllability of the etching process. In this way, not only the cleaning effect of the battery wafer is improved, but also the warpage degree of the battery wafer can be reduced. Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0042] Figure 1 It is a flowchart of the method for reducing the warpage degree in the etching process of the battery wafer according to an embodiment of the present application;

[0043] Figure 2 It is a schematic structural diagram of a battery wafer precursor according to an embodiment of the present application;

[0044] Figure 3 It is a schematic structural diagram of a wet chemical processing machine according to an embodiment of the present application;

[0045] Figure 4 It is a schematic structural diagram of a wet chemical processing machine according to another embodiment of the present application.

[0046] Reference Signs:

[0047] 1. Battery wafer precursor; 2. Silicon wafer; 201. Backlight surface of the silicon wafer; 202. Light-facing surface of the silicon wafer; 3. Tunneling oxide layer; 31. First tunneling oxide layer; 32. Second tunneling oxide layer; 4. Doped polysilicon layer; 41. Boron-doped polysilicon layer; 5. Borosilicate glass layer; 42. Phosphorus-doped polysilicon layer; 6. Phosphosilicate glass layer; 100. Wet chemical processing machine; 10. Warpage degree detection unit; 11. First sensor; 12. Transmitter; 13. Industrial control computer; 20. Spraying unit; 21. Spraying member; 22. Conveying member; 23. Second sensor; 30. Etching unit; 40. Loading unit; 50. Unloading unit. Detailed Implementation Modes

[0048] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation modes of the present application in conjunction with the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0049] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or there can also be an intermediate component. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be an intermediate component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of the present application are only for illustrative purposes and do not represent the only implementation mode.

[0050] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0051] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first feature is in direct contact with the second feature, or the first feature is indirectly in contact with the second feature through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature has a lower horizontal height than the second feature.

[0052] Unless otherwise defined, all technical and scientific terms used in the specification of the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific implementation modes and are not intended to limit the present application. The term "and / or" used in the specification of the present application includes any and all combinations of one or more of the related listed items.

[0053] In a first aspect, the present application provides a method for reducing the warpage degree during the etching process of a wafer, which is applicable to a wet chemical chain machine 100. Along the transportation direction of the wafer precursor 1, the wet chemical chain machine 100 includes a warpage degree detection unit 10, a spraying unit 20, and an etching unit 30 arranged in sequence; the warpage degree detection unit 10 includes an industrial control computer 13, a first sensor 11, a transmitter 12, and a receiver that are communicatively connected to the industrial control computer 13; the spraying unit 20 includes a spraying member 21 for spraying a cleaning liquid onto the wafer precursor 1 and a conveying member 22 for conveying the wafer precursor 1, and the conveying member 22 is arranged below the spraying member 21.

[0054] Please refer to Figure 1 , the method for reducing the warpage degree during the etching process of the wafer includes:

[0055] S100: Obtain the wafer precursor 1, which includes a silicon wafer 2, a tunneling oxide layer 3, a doped polysilicon layer 4, and a phosphosilicate glass layer 6 that are sequentially stacked on the silicon wafer 2;

[0056] S200: After the first sensor 11 senses that the wafer precursor 1 reaches the target position, an induction signal is generated, and the industrial control computer 13 receives the induction signal and starts the transmitter 12;

[0057] S300: The light emitted by the transmitter 12 is reflected by the backlight surface of the wafer precursor 1 to the receiver, and the industrial control computer 13 calculates the warpage degree of the wafer precursor 1 based on the running time of the light;

[0058] S400: The industrial control computer 13 calculates the adjusted spraying flow rate of the spraying member 21 and the adjusted running speed of the conveying member 22 according to the warpage degree;

[0059] S500: The wafer precursor 1 passes through the area where the spraying member 21 is located at the running speed, and the spraying member 21 sprays the cleaning liquid onto the backlight surface of the wafer precursor 1 at the spraying flow rate so that a liquid film covers the backlight surface of the wafer precursor 1, and the etching unit 30 performs wet etching on the light-facing surface of the wafer precursor 1.

[0060] It is understandable that during the production process of TBC solar cells, especially during the production process of the solar cell precursor 1, it is necessary to remove the PSG oxide layer that is circumferentially plated on the light-facing surface and the side surfaces of the solar cell precursor 1 to prevent short circuits between the top and bottom. However, during the process of removing the circumferential plating, it is necessary to avoid damaging the backlight surface of the solar cell precursor 1. Therefore, high requirements are imposed on the etching line and the etching amount. When the solar cell precursor 1 enters the etching unit 30, the "yellow smoke" generated by the chemicals used in etching will corrode the backlight surface of the solar cell precursor 1 and may also cause the phenomenon of over-etching at the edges. This phenomenon is an uncontrollable factor that affects the quality of the solar cell precursor 1 during production. Therefore, before wet etching, it is necessary to spray a liquid film on the backlight surface of the solar cell precursor 1 to isolate the damage to the backlight surface of the solar cell precursor 1 during the etching process.

[0061] In this embodiment, by detecting and calculating the warpage degree of the solar cell precursor 1 and automatically and specifically adjusting the spraying flow rate of the spraying member 21 in the spraying device and the running speed of the conveying member 22 for transporting the solar cell precursor 1 in the spraying unit 20 according to the obtained warpage degree, the amount of the liquid film covering the solar cell precursor 1 can be accurately adjusted. By accurately adjusting the amount of the liquid film covering the solar cell precursor 1, firstly, the amount of the liquid film can adjust the surface tension of the solar cell precursor 1, so that the etching solution used in the wet etching process uniformly covers the light-facing surface of the solar cell precursor, enabling the wet etching reaction to proceed synchronously, avoiding the reaction rate in a local area of the solar cell precursor 1 being too fast (generating tensile stress) or too slow (generating compressive stress), thereby reducing the stress gradient on the solar cell precursor 1 and avoiding the phenomenon of uneven local etching on the solar cell precursor during wet etching, and further improving the phenomenon of poor uniformity, over-etching / remaining oxide layer on the solar cell after etching and cleaning, and further ensuring the stability and controllability of the etching process, not only improving the cleaning effect of the solar cell but also reducing the warpage degree of the solar cell. Secondly, the liquid film has a certain supporting effect on the solar cell precursor 1, reducing the deformation of the solar cell precursor 1 caused by its own gravity or external force during the wet etching process, which is beneficial to reducing the warpage degree of the solar cell precursor 1 and further reducing the warpage degree of the solar cell. Thirdly, since the wet etching process of the solar cell precursor 1 is an exothermic process, during the wet etching process, the problem of uneven heat absorption may occur in different parts of the solar cell precursor 1, resulting in thermal stress on the solar cell precursor 1, while the liquid film can dissipate heat evenly, reducing the generation of thermal stress, thereby reducing the warpage degree of the solar cell precursor 1 and further reducing the warpage degree of the solar cell.

[0062] It should be noted that the cleaning liquid sprayed towards the backlight surface of the solar cell precursor 1 in this application is water. In other embodiments, other liquids can also be used to replace water to clean and protect the backlight surface of the solar cell precursor 1.

[0063] In one embodiment, refer toFigure 2 In step S100, the doped polysilicon layer 4 includes a boron-doped polysilicon layer 41 and a phosphorus-doped polysilicon layer 42, the tunneling oxide layer 3 includes a first tunneling oxide layer 31 and a second tunneling oxide layer 32, and the method for obtaining the cell precursor 1 includes:

[0064] S110: Perform the first double-sided polishing on the silicon wafer 2;

[0065] S120: Sequentially form the first tunneling oxide layer 31 and the boron-doped polysilicon layer 41 on both sides of the silicon wafer 2;

[0066] S130: Perform the first laser patterning on the backlight side of the silicon wafer 2 to remove the borosilicate glass layer 5 in the N region and the isolation region;

[0067] S140: Perform the second double-sided polishing on the silicon wafer 2 to remove the first tunneling oxide layer 31 and the boron-doped polysilicon layer 41 in the N region and the isolation region;

[0068] S150: Sequentially form the second tunneling oxide layer 32 and the phosphorus-doped polysilicon layer 42 on both sides of the silicon wafer 2;

[0069] S160: Perform the second laser patterning on the backlight side of the silicon wafer 2 to remove the phosphosilicate glass layer 6 in the P region and the isolation region, obtaining the cell precursor 1.

[0070] In this embodiment, by depositing the tunneling oxide layer 3 and the doped polysilicon layer 4 on both sides, the symmetry of the structure is improved, the risk of the doped polysilicon layer 4 being plated around is reduced, the difficulty of the wet process is lowered. At the same time, through laser patterning and wet etching, the preparation of the cell precursor 1 of the TBC cell can be realized without preparing a mask layer, effectively simplifying the process flow. Moreover, the TBC solar cell prepared using the cell precursor 1 has high conversion performance and is suitable for large-scale production.

[0071] It can be understood that both sides of the silicon wafer 2 refer to the backlight side 201 of the silicon wafer and the frontlight side 202 of the silicon wafer. The backlight side of the cell precursor 1 (i.e., the backlight side of the silicon wafer 2) includes an N region, a P region, and an isolation region. Among them, the isolation region is at the gap between the N region and the P region; the silicon wafer 2 is preferably an N-type silicon wafer 2.

[0072] It should be noted that steps S110 to S160 can be prepared according to existing methods, which will not be elaborated in this embodiment. This embodiment has no special limitations on the thickness and materials of the first tunneling oxide layer 31, the boron-doped polysilicon layer 41, the second tunneling oxide layer 32, and the phosphorus-doped polysilicon layer 42.

[0073] In one embodiment, in step S200, after the first inductor 11 senses that the cell precursor 1 reaches the target position, an induction signal is generated, and the industrial control computer 13 receives the induction signal and starts the transmitter 12.

[0074] The target position refers to the position where the cell precursor 1 can receive the light from the transmitter 12 and can reflect the light to the receiver. Schematically, the first sensor 11 can use a photoelectric sensor, a position sensor, etc., and this application does not limit this. Schematically, the transport unit is arranged through the warpage detection unit 10 and the spray unit 20 to transport the cell precursor 1 between the warpage detection unit 10 and the spray unit 20.

[0075] In one embodiment, in step S300, the light emitted by the transmitter 12 is reflected by the backlight surface of the cell precursor 1 to the receiver, and the industrial computer 13 calculates the warpage of the cell precursor 1 according to the running time of the light.

[0076] In this embodiment, the industrial computer 13 calculates the warpage of the cell precursor 1 according to the running time of the light, including: the industrial computer 13 constructs a warpage model of the cell precursor 1 according to the running time of the light, and then calculates the warpage of the cell precursor 1 according to the warpage model.

[0077] It is understandable that, since the speed of light is fixed, the distance between the backlight surface of the cell precursor 1 and the receiver or transmitter 12 can be obtained by detecting the running time of the light. Compared with directly measuring the warping height of each key point on the cell precursor 1 and the distance from the receiver or transmitter 12, measuring the running time of the light is simpler.

[0078] Schematically, the method for constructing the warpage model of the cell precursor 1 is:

[0079] (1) Obtaining the distance values between multiple key points on the backlight surface of the cell precursor 1 and the receiver through the running time of the light;

[0080] (2) Use geometric relationships (such as triangulation) to convert the distance value data into three-dimensional coordinates, and then construct a warping model of the backlight surface of the battery cell precursor 1.

[0081] In other embodiments, other existing technologies may also be used to construct a warping model of the cell precursor 1 .

[0082] Schematically, the method for calculating the warpage of the cell precursor 1 according to the warpage model is:

[0083] (1) Data preprocessing: remove noise points and smooth the above distance value data.

[0084] (2) Reference plane fitting: Use the least squares method or RANSAC algorithm to fit the ideal plane.

[0085] (3) Deviation analysis: Calculate the vertical deviation of each key point from the reference plane to generate a deviation distribution map. The reference plane needs to be calibrated in advance.

[0086] (4) Quantify the degree of warping. Schematically, the following method can be used to quantify the warping degree:

[0087] ① Regional extreme value method: Take the sum of the absolute values of the largest positive and negative deviations in the distance value data of all key points as the warping degree of the battery precursor 1.

[0088] ② Maximum deviation method: Take the maximum absolute deviation value among all key points as the warping degree of the battery precursor 1.

[0089] ③ Root mean square error (RMSE): Calculate the root mean square value of the deviations of all key points to comprehensively evaluate the warping degree of the battery precursor 1.

[0090] ④ Area weighting method: Assign higher weights to high-deviation regions (such as the edges), and calculate the comprehensive warping index as the warping degree of the battery precursor 1.

[0091] It should be noted that the warping degree of the battery precursor 1 can be measured under the static condition of the battery precursor 1 to avoid the influence of the movement of the battery precursor 1 on the reflection of light, thereby improving the detection accuracy.

[0092] In step S400, the industrial control computer 13 calculates the adjusted spraying flow rate of the spraying member 21 and the adjusted running speed of the conveying member 22 according to the warping degree, so as to adjust the amount of liquid film covering the battery precursor 1, so that the liquid film can evenly cover the backlight surface of the battery precursor 1. In this way, the phenomenon of poor uniformity and over-etching / oxidation layer residue on the battery after etching and cleaning can be improved, and the stability and controllability of the etching process can be ensured. The stability of the etching process not only improves the cleaning effect of the battery, but also can reduce the warping degree of the battery.

[0093] In one embodiment, define the adjusted running speed of the conveying member 22 as v, that is, the battery precursor 1 passes through the area where the spraying member 21 is located at the running speed v, and the expression of v is as follows:

[0094] ;

[0095] where, v0 represents the initial running speed of the conveying member 22, the value range of v0 is 0.8m / s to 3.2m / s, α represents the proportional coefficient of the speed of the conveying member 22, δ represents the warping degree of the battery precursor 1, L cell represents the length of the battery precursor 1, L film represents the diffusion length of the cleaning liquid on the battery precursor 1, and L film ≥ Lcell , to ensure that the liquid film can completely cover the backlight surface of the battery precursor 1, where k represents a correction factor. The proportionality coefficient α needs to be calibrated through process experiments, and the specific calibration method can be calibrated using conventional technical means in the art, which will not be elaborated in this application.

[0096] It can be understood that during the cleaning process of the battery precursor 1, the length of the liquid film covering the backlight surface of the battery precursor 1 consists of two parts. One part is the length L of the liquid film directly sprayed by the spraying member 21 of the spraying unit 20 on the backlight surface of the battery precursor 1 nozzle , and the other part is the diffusion length L of the sprayed cleaning liquid on the backlight surface of the battery precursor 1 film . Among them, the diffusion length L film is jointly affected by the gravity of water, surface tension, and the initial running speed of the conveying member 22.

[0097] The diffusion length L of the sprayed cleaning liquid on the backlight surface of the battery precursor 1 film has the following expression:

[0098] ;

[0099] Among them, ρ represents the density of the cleaning liquid, g represents the acceleration due to gravity of the cleaning liquid, h represents the initial liquid film thickness, that is, the thickness of the liquid film sprayed by the spraying member 21 on the backlight surface of the battery precursor 1 before diffusion. t spread represents the diffusion time of the sprayed cleaning liquid on the backlight surface of the battery precursor 1, and μ represents the viscosity of the cleaning liquid.

[0100] Schematically, in this embodiment, since water is used as the cleaning liquid, when calculating the diffusion length L film , the density of water is taken as 1000 kg / m³, g is taken as 9.8 m / s², the unit of h is meters (m), and the unit of t spread is seconds (s). The viscosity μ of water at 20°C is taken as 1.002×10 −3 Pa·s.

[0101] It should also be noted that the influencing factors of the liquid film diffusion time t spread include: the physical properties (viscosity, density, surface tension) of the liquid for cleaning the backlight surface of the battery precursor 1, process parameters (running speed of the conveying member 22 in the spraying unit 20, spraying flow rate of the spraying member 21, spraying head design of the spraying member 21), characteristics of the battery precursor 1 (warpage, roughness, hydrophilicity), environmental and geometric parameters (temperature, size of the battery precursor 1). When the cleaning liquid formula is stable, the batches of battery precursors are consistent, and the equipment and environment are controlled, and since the distance that the liquid film needs to diffuse on the backlight surface of the battery precursor 1 is fixed, therefore, when calculating the diffusion length Lfilm When t spread is regarded as a fixed value. By reasonably assuming this fixed value, the complexity of process control can be significantly reduced, but regular calibration and outlier monitoring are still required. The methods for assuming this fixed value, calibration, and outlier monitoring can use conventional techniques in the art, and are not elaborated herein in this embodiment.

[0102] Schematically, the size of the wafer precursor 1 is 182 mm × 184 mm, and the length L of the wafer precursor 1 cell is 184 mm.

[0103] It should also be noted that before the transport member transports the wafer precursor 1 below the spraying member 21, the speed of the transport member is still the initial running speed v0. Before the spraying member 21 starts spraying the cleaning liquid, the speed of the transport member is adjusted to the calculated running speed v.

[0104] In one embodiment, the adjusted spraying flow rate of the spraying member 21 is defined as Q, and the expression of Q is as follows:

[0105] ;

[0106] wherein, Q0 represents the initial spraying flow rate of the spraying member 21, and β represents the proportionality coefficient of the spraying flow rate of the spraying member 21. The proportionality coefficient β needs to be calibrated through process experiments, and the specific calibration method can be calibrated by using conventional technical means in the art, and is not elaborated herein in this application. In this way, it can be ensured that there is enough cleaning liquid to diffuse on the backlight surface of the wafer precursor 1, so that the liquid film can completely cover the backlight surface of the wafer precursor 1.

[0107] Schematically, the expression of the initial spraying flow rate Q0 of the spraying member 21 is as follows:

[0108] ;

[0109] wherein, W represents the width of the wafer precursor 1, and t on represents the spraying time, that is, the working time of the spraying member 21. Before the spraying flow rate of the spraying member 21 is adjusted, the initial spraying liquid volume of the spraying member 21 needs to cover the surface area of the wafer precursor 1, that is, W*L on within the spraying time t cell .

[0110] The spraying time t on has the following expression:

[0111] ;

[0112] wherein, L nozzleIt represents the liquid film length (unit: m) directly sprayed on the backlight surface of the battery precursor 1 by the spraying part 21 per unit time, that is, the covering length of the liquid spraying amount of the spraying part 21 per unit time on the backlight surface of the battery precursor 1. In this way, it is ensured that when the spraying ends, the cleaning liquid sprayed by the spraying part 21 can spread to the end of the battery.

[0113] Further, in step S400, the industrial control computer 13 calculates the adjusted spraying flow rate of the spraying part 21 and the adjusted running speed of the conveying part 22. The method further includes: measuring the actual diffusion length L of the cleaning liquid on the battery precursor 1 film,real , judging the actual diffusion length L film,real and the diffusion length L film Whether the numerical relationship between them is within the numerical range of the correction coefficient k. If it is not within the numerical range of the correction coefficient k, it means that a large change has occurred in the process of obtaining the battery precursor 1, and then the correction coefficient k, the proportionality coefficient α of the speed of the conveying part 22, the proportionality coefficient β of the spraying flow rate of the spraying part 21, the length L of the battery precursor 1 cell And other parameters; if it is within the numerical range of the correction coefficient k, no other actions are taken.

[0114] Schematically, a laser rangefinder or an optical sensor can be used to measure the actual diffusion length L film,real , and a high-precision flowmeter is used to measure the spraying flow rate Q.

[0115] In this embodiment, k ∈ [0.8, 1.2]. In other embodiments, the correction coefficient k needs to be calibrated by experiments. In this embodiment, the diffusion length L of the cleaning liquid sprayed on the battery precursor 1 is used film To calibrate the correction coefficient k. At this time, the expression of the correction coefficient k is as follows:

[0116] ;

[0117] Among them, the correction coefficient k at this time represents the deviation between the calculated diffusion length L film and the measured actual diffusion length L film,real . By changing the process parameters (the running speed v of the conveying part 22, the spraying flow rate Q of the spraying part 21), measuring the actual diffusion length L of the cleaning liquid on the battery precursor 1 film,real , the value range of the correction coefficient k can be obtained.

[0118] The calibration method of the correction coefficient k in this embodiment is as follows:

[0119] S1: Basic data acquisition. The basic data includes the running speed v, the spraying flow rate Q, and the actual diffusion length L film,real .

[0120] Specifically, the basic data collection includes:

[0121] S101: While keeping the running speed v constant, adjust the spray flow rate Q in gradients, measure and record the actual diffusion length L film,real ; For each spray flow rate Q, measure at least 5 times and take the average value as the final actual diffusion length L film,real to reduce random errors;

[0122] S102: While keeping the spray flow rate Q constant, adjust the running speed v in gradients and record the actual diffusion length L film,real ; For each running speed v, measure at least 5 times and take the average value as the final actual diffusion length L film,real to reduce random errors;

[0123] S2: Fitting and optimization of basic data.

[0124] Specifically, the fitting and optimization of basic data include:

[0125] S201: For each set of basic data (running speed v, spray flow rate Q, and the actual diffusion length L measured at this running speed v and this spray flow rate Q film,real is a set of basic data), calculate the corresponding value of the correction coefficient k;

[0126] S202: Analyze the relationship between the value of the correction coefficient k and the process parameters, and determine whether interval calibration is required; if the correction coefficient k changes significantly with the running speed v or the spray flow rate Q, then the value of the correction coefficient k is taken as 1. At this time, the numerical range of the correction coefficient k is [0.95, 1.05]; if the change of the correction coefficient k with the running speed v or the spray flow rate Q is not significant, then take the average value of all calculated correction coefficients k as the value of the correction coefficient k, and take all calculated correction coefficients k as the numerical range of the correction coefficient k;

[0127] Preferably, when the correction coefficient k changes significantly with the running speed v or the spray flow rate Q, the correction coefficient k can also be calibrated in segments. The value and range of the correction coefficient k can be fitted by establishing a linear or polynomial, such as k = f(v).

[0128] S203: Error optimization;

[0129] Due to the accuracy fluctuation of the laser rangefinder or optical sensor, the measured actual diffusion length L film,real may have certain errors, or due to the fluctuation of the flowmeter, the measured spray flow rate Q has certain errors, or due to the temperature change, the viscosity of the cleaning liquid fluctuates, which in turn causes the measured actual diffusion length L film,realThere is a certain error. Therefore, at least one of the following methods can be used to optimize the above error:

[0130] (1) Verification by multiple groups of experiments: Repeat the above experiments under different environmental conditions to evaluate the stability of the correction coefficient k.

[0131] (2) Introduction of temperature compensation: If the correction coefficient k is significantly affected by temperature, establish a correction formula of k = f(T), where T represents temperature.

[0132] (3) Machine learning assistance: Collect a large amount of experimental data and train a neural network to predict the correction coefficient k to adapt to complex non-linear relationships.

[0133] This embodiment takes into account both theoretical rigor and engineering practicality, can significantly improve the prediction accuracy of the running speed v, helps to reduce the warpage of the battery wafer precursor, and further reduces the warpage of the battery wafer.

[0134] In one embodiment, the spraying unit 20 further includes a second sensor. After the industrial control computer 13 calculates the adjusted spraying flow rate of the cleaning liquid spraying member 21 and the adjusted running speed of the cleaning liquid conveying member 22, when the second sensor detects that the battery wafer precursor 1 enters the spraying unit 20 and after a delay time t delay later, the spraying member 21 starts to spray the cleaning liquid towards the battery wafer precursor 1. In this embodiment, the spraying member 21 sprays water vertically downward, and the area where the spraying member 21 is located is the area where the battery wafer precursor 1 can be sprayed. Also, since the length of the spraying unit 20 is greater than the length of the battery wafer precursor 1, in the transportation direction of the battery wafer precursor 1, the battery wafer precursor 1 needs to be transported a certain distance on the transportation member before reaching the area where the spraying member 21 is located. Therefore, after a delay time t delay later, the spraying member 21 starts to spray the cleaning liquid towards the battery wafer precursor 1, which can avoid wasting the cleaning liquid.

[0135] In other embodiments, the spraying member 21 can also be set at a certain angle, and this application does not limit the comparison, as long as the cleaning liquid can be sprayed on the backlight surface of the battery wafer precursor 1, and the delay time t delay is calibrated in advance through experiments.

[0136] Further, the expression of the delay time t delay is: ; where the position where the battery wafer precursor 1 just enters the spraying unit 20 is defined as the first position, D senorIt represents the distance between the first position and the spraying member 21 in the moving direction of the battery wafer precursor 1. In this embodiment, along the transportation direction of the battery wafer precursor 1, the end of the spraying unit 20 where the battery wafer precursor 1 enters is defined as the front end of the spraying unit 20, the end of the battery wafer precursor 1 that enters the spraying unit 20 first is defined as the front end of the battery wafer precursor 1, and the relatively distributed end is the end of the battery wafer precursor 1. The distance between the spraying member 21 and the front end of the spraying unit 20 is D senor When the battery wafer precursor 1 just enters the spraying unit 20, the distance between the battery wafer precursor 1 and the spraying member 21 is also D senor . Therefore, after the spraying member 21 passes through the delay time t delay and then starts to spray the cleaning liquid towards the battery wafer precursor 1, it can avoid wasting the cleaning liquid.

[0137] In one embodiment, the method further includes: after the spraying member 21 passes through the time T, it stops spraying the cleaning liquid towards the battery wafer precursor 1, and the time T satisfies the following relational expression: ; where L nozzle represents the covering length of the liquid spraying amount per unit time of the spraying member 21 on the backlight surface of the battery wafer precursor 1, L cell represents the length of the battery wafer precursor 1, and v represents the adjusted running speed of the conveying member 22, that is, the actual speed of the battery wafer precursor 1 passing through the area where the spraying member 21 is located. It can be understood that when the total amount of the cleaning liquid sprayed by the spraying member 21 can completely cover the backlight surface of the battery wafer precursor 1 after diffusion, the spraying member 21 can stop spraying the cleaning liquid towards the battery wafer precursor 1, instead of waiting until the end of the battery wafer precursor 1 leaves the area where the spraying member 21 is located before stopping spraying the cleaning liquid. In this way, it can avoid wasting the cleaning liquid.

[0138] It should be noted that in this embodiment, T is calculated starting from when the second sensor 23 detects that the battery wafer precursor 1 just enters the spraying unit 20. In other embodiments, T can also be calculated starting from other positions of the battery wafer precursor 1. At this time, the stop spraying condition of the spraying member 21 can be adaptively modified.

[0139] In one embodiment, in step S500, the battery wafer precursor 1 passes through the area where the spraying member 21 is located at the running speed, and the spraying member 21 sprays the cleaning liquid onto the backlight surface of the battery wafer precursor 1 at the spraying flow rate, so that a liquid film is covered on the backlight surface of the battery wafer precursor 1, and the etching unit 30 performs wet etching on the light-facing surface of the battery wafer precursor 1.

[0140] All the layers grown on the light-facing surface of the battery wafer precursor 1 are removed by wet etching, including the first tunneling oxide layer 31, boron-doped polysilicon layer 41, borosilicate glass layer 5, second tunneling oxide layer 322, phosphorus-doped polysilicon layer 42, and phosphosilicate glass layer 6. It should be noted that during wet etching, the overcoating layer grown on the side of the silicon wafer 2 can also be removed. Wet etching adopts the conventional methods in this industry and will not be elaborated in this embodiment.

[0141] In a second aspect, the present application also provides a method for manufacturing a TBC battery wafer. This manufacturing method uses the method for reducing the warpage degree during the etching process of the battery wafer in any of the above embodiments. All the layers on the light-facing surface of the battery wafer precursor 1 are removed by wet etching to obtain a battery wafer intermediate; and

[0142] S600: Perform double-sided texturing on the battery wafer intermediate, etch the P region on the backlight surface to the boron-doped polysilicon layer 41, the N region to the phosphorus-doped polysilicon layer 42, and the isolation region to the silicon wafer 2, and form a textured surface on the isolation region on the backlight surface of the silicon wafer and the light-facing surface of the silicon wafer;

[0143] S700: Deposit a passivation layer and an antireflection layer on both sides of the battery wafer intermediate;

[0144] S800: Prepare a positive electrode on the P region on the back of the battery wafer intermediate and a negative electrode on the N region to obtain a TBC battery wafer.

[0145] In the above method for manufacturing a TBC battery, during the process of obtaining the battery wafer intermediate, the battery wafer precursor 1 can be precisely cleaned, improving the phenomena of poor uniformity, over-etching / oxidation layer residue on the battery wafer after etching and cleaning, thereby ensuring the stability and controllability of the etching process. This not only improves the cleaning effect of the battery wafer but also reduces the warpage degree of the battery wafer. Therefore, the TBC battery wafer prepared using the above battery wafer intermediate has higher quality.

[0146] It should be noted that steps S600, S700, and S800 can be prepared according to existing methods and will not be elaborated in this embodiment. There are no special restrictions on the thickness and materials of the passivation layer and the antireflection layer in this embodiment.

[0147] In a third aspect, the present application also provides a TBC battery wafer obtained by the method for manufacturing a TBC battery wafer in the above embodiment. In the TBC battery, the uniformity of the tunneling oxide layer 3 and the doped polysilicon layer 4 thin films is good, the passivation performance is excellent, and the TBC battery has high conversion efficiency, large open-circuit voltage, and large current density.

[0148] In a fourth aspect, the present application also provides a wet etching chain machine 100 for implementing the method for reducing the warpage degree during the etching process of the battery wafer in any of the above embodiments. As Figure 3 shown, along the transportation direction of the battery wafer precursor 1 (such asFigure 3 As shown by the arrow in Figure 3 , the wet chemical chain machine 100 includes a warp detection unit 10, a spraying unit 20, and an etching unit 30 arranged in sequence; among them,

[0149] The warp detection unit 10 includes a first sensor 11, a transmitter 12, a receiver (not shown in the figure), and an industrial control computer 13. The first sensor 11, the transmitter 12, and the receiver are all communicatively connected to the industrial control computer 13. Among them, the first sensor 11 is configured to sense whether the battery precursor 1 reaches the target position and generate a sensing signal. The transmitter 12 is configured to emit light towards the battery precursor 1. The receiver is configured to receive the light reflected by the backlight surface of the battery precursor 1. The industrial control computer 13 is configured to receive the sensing signal and start the transmitter 12, calculate the warp of the battery precursor 1 based on the running time of the light, calculate the adjusted spraying flow rate of the spraying member 21 and the adjusted running speed of the conveying member 22, and adjust the spraying flow rate of the spraying member 21 and the running speed of the conveying member 22.

[0150] The spraying unit 20 includes a spraying member 21 and a conveying member 22 for conveying the battery precursor 1. The conveying member 22 is arranged below the spraying member 21. The spraying member 21 is configured to spray a cleaning liquid onto the backlight surface of the battery precursor 1;

[0151] The etching unit 30 is configured to perform wet etching on the light-facing surface of the battery precursor 1.

[0152] Schematically, the conveying member 22 can use rollers arranged in sequence or a belt. The present application does not limit this, as long as it can transport the battery.

[0153] Schematically, multiple receivers can be provided to fully receive the light reflected by the battery precursor 1 and avoid missing light. The settings of the receiver and the reflector can refer to the setting methods in the prior art, and the present application does not limit this.

[0154] Further, the wet chemical chain machine 100 further includes a loading unit 40 and an unloading unit 50. Along the transportation direction of the battery precursor 1, the loading unit 40 is arranged upstream of the warp detection unit 10 to transport the battery precursor 1 into the warp detection unit 10; the unloading device is arranged downstream of the etching unit 30 to receive the battery intermediate output from the etching unit 30.

[0155] Such as Figure 4As shown in the figure, the working principle of the wet-process chain machine 100 is as follows: The feeding unit 40 transports the battery precursor 1 to the warpage detection unit 10. After the first inductor 11 senses that the battery precursor 1 reaches the target position, it generates an induction signal and sends the induction signal to the industrial control computer 13. The industrial control computer 13 receives the induction signal and activates the transmitter 12. The light emitted by the transmitter 12 is reflected by the backlight surface of the battery precursor 1 to the receiver. The industrial control computer 13 calculates the warpage of the battery precursor 1 based on the running time of the light, and then calculates the adjusted spraying flow rate of the spraying part 21 and the adjusted running speed of the conveying part 22 according to the warpage. At this time, the battery precursor 1 still moves at the initial running speed until the second sensor 23 detects the battery precursor 1. After a delay time t delay later, that is, the front end of the battery precursor 1 enters the area where the spraying part 21 is located. At this time, the conveying part transports the battery precursor 1 through the area where the spraying part 21 is located at the adjusted running speed, and the spraying part 21 sprays the cleaning liquid onto the backlight surface of the battery precursor 1 at the spraying flow rate. Subsequently, the battery precursor 1 with its backlight surface covered by the liquid film enters the etching unit 30. The etching unit 30 performs wet etching on the light-facing surface of the battery precursor 1 to remove all layers on the light-facing surface of the battery precursor 1 and obtain the battery intermediate. The battery intermediate enters the blanking machine from the etching unit 30 and is further processed into the finished TBC battery sheet.

[0156] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0157] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A method for reducing the warpage degree during the etching process of a battery slice, characterized in that, Applicable to a wet-type chain machine, along the transport direction of the battery wafer precursor, the wet-type chain machine includes a warp detection unit, a spraying unit, and an etching unit arranged in sequence; the warp detection unit includes an industrial control computer and a first sensor, a transmitter, and a receiver communicatively connected to the industrial control computer; the spraying unit includes a spraying member and a conveying member for conveying the battery wafer precursor, and the conveying member is arranged below the spraying member; The method includes: Obtaining a battery wafer precursor, the battery wafer precursor including a silicon wafer and a tunneling oxide layer, a doped polysilicon layer, and a phosphosilicate glass layer sequentially stacked on the silicon wafer; After the first sensor senses that the battery wafer precursor reaches the target position, an induction signal is generated, and the industrial control computer receives the induction signal and activates the transmitter; The light emitted by the transmitter is reflected by the backlight surface of the battery wafer precursor to the receiver, and the industrial control computer calculates the warp of the battery wafer precursor according to the running time of the light; The industrial control computer calculates the adjusted spraying flow rate of the spraying member and the adjusted running speed of the conveying member according to the warp; The battery wafer precursor passes through the area where the spraying member is located at the running speed, and the spraying member sprays a cleaning liquid onto the backlight surface of the battery wafer precursor at the spraying flow rate, so that a liquid film covers the backlight surface of the battery wafer precursor, and the etching unit performs wet etching on the light-facing surface of the battery wafer precursor.

2. The method according to claim 1, wherein Define the adjusted running speed of the conveying member as v, and the expression of v is as follows: ； Among them, v0 represents the initial running speed of the conveying member, α represents the proportionality coefficient of the conveying member speed, δ represents the warpage of the battery precursor, L cell represents the length of the battery precursor, L film represents the diffusion length of the cleaning liquid on the battery precursor, and L film ≥L cell , and k represents the correction coefficient.

3. The method according to claim 2, wherein Define the adjusted spraying flow rate of the spraying member as Q, and the expression of Q is as follows: ； Wherein, Q0 represents the initial spraying flow rate of the spraying member, and β represents the proportionality coefficient of the spraying flow rate of the spraying member.

4. The method according to claim 1, wherein The spraying unit further includes a second sensor. After the industrial control computer calculates the adjusted spraying flow rate of the spraying member and the adjusted running speed of the conveying member, when the second sensor detects that the battery precursor enters the spraying unit and after a delay time t delay has passed, the spraying member starts to spray the cleaning liquid towards the battery precursor.

5. The method according to claim 4, wherein The delay time t delay has the following expression: ； Among them, the position where the battery precursor just enters the spraying unit is defined as the first position, D senor represents the distance between the first position and the spraying member in the moving direction of the battery precursor, and v0 represents the initial running speed of the conveying member.

6. The method according to claim 5, characterized in that The method further includes: the spraying member stops spraying the cleaning liquid towards the battery wafer precursor after a time T, and the time T satisfies the following relational expression: ； Among them, L cell represents the length of the battery precursor, and L nozzle represents the coverage length of the liquid spraying amount of the spraying member per unit time, and v represents the adjusted running speed of the conveying member.

7. The method according to claim 1, wherein The tunneling oxide layer includes a first tunneling oxide layer and a second tunneling oxide layer, the doped polysilicon layer includes a boron-doped polysilicon layer and a phosphorus-doped polysilicon layer, and the method for obtaining the battery wafer precursor includes: Performing first double-sided polishing on the silicon wafer; Sequentially forming the first tunneling oxide layer and the boron-doped polysilicon layer on both sides of the silicon wafer; Performing first laser patterning on the backlight surface of the silicon wafer to remove the phosphosilicate glass layer in the N region and the isolation region; Performing second double-sided polishing on the silicon wafer to remove the first tunneling oxide layer and the boron-doped polysilicon layer in the N region and the isolation region; Sequentially forming the second tunneling oxide layer and the phosphorus-doped polysilicon layer on both sides of the silicon wafer; Performing second laser patterning on the backlight surface of the silicon wafer to remove the phosphosilicate glass layer in the P region and the isolation region to obtain the battery wafer precursor.

8. A preparation method of a TBC cell, characterized in that, Using the method for reducing warp during the etching process of a battery wafer including any one of claims 1 to 7, removing all layers on the light-facing surface of the battery wafer precursor by wet etching to obtain a battery wafer intermediate; and Double-side texturing is performed on the battery cell intermediate, etching the P region on the backlight side to the boron-doped polysilicon layer, the N region to the phosphorus-doped polysilicon layer, and the isolation region to the silicon wafer, and a textured surface is formed on the isolation region of the backlight side of the silicon wafer and the light-facing side of the silicon wafer; A passivation layer and an antireflection layer are deposited on both sides of the battery cell intermediate; A positive electrode is prepared on the P region on the back of the battery cell intermediate, and a negative electrode is prepared on the N region to obtain a TBC battery cell.

9. A TBC battery cell prepared by the preparation method according to claim 8.

10. A wet type chain machine, characterized in that, A method for reducing the warpage degree in the etching process of the battery cell according to any one of claims 1 to 8, characterized in that, along the transport direction of the battery cell precursor, the wet chemical chain machine includes a warpage degree detection unit, a spraying unit, and an etching unit arranged in sequence; The warpage degree detection unit includes a first sensor, a transmitter, a receiver, and an industrial control computer. The first sensor, the transmitter, and the receiver are all communicatively connected to the industrial control computer. Among them, the first sensor is configured to sense whether the battery cell precursor reaches the target position and generate a sensing signal. The transmitter is configured to emit light towards the battery cell precursor. The receiver is configured to receive the light reflected by the backlight side of the battery cell precursor. The industrial control computer is configured to receive the sensing signal and start the transmitter, calculate the warpage degree of the battery cell precursor based on the running time of the light, calculate the adjusted spraying flow rate of the spraying part and the adjusted running speed of the conveying part, and adjust the spraying flow rate of the spraying part and the running speed of the conveying part; The spraying unit includes a spraying part and a conveying part for transporting the battery cell precursor. The conveying part is arranged below the spraying part, and the spraying part is configured to spray a cleaning liquid on the backlight side of the battery cell precursor; The etching unit is configured to perform wet etching on the light-facing side of the battery cell precursor.

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