Method for solving TOPCon battery slice alkali polishing adhesion with liquid

Abstract

The invention discloses a method for solving the problem that a TOPCon battery slice adheres to the slice and carries liquid during alkali polishing. The method specifically comprises the following operation steps that a silicon slice is pre-cleaned; polishing the back surface of the silicon wafer by using a mixed solution of sodium hydroxide and an alkali polishing additive; putting the silicon wafer subjected to alkali polishing into a mixed solution of hydrogen peroxide, sodium hydroxide and pure water for cleaning; pickling the silicon wafer by using a mixed solution of hydrochloric acid, hydrofluoric acid and pure water; washing impurities and residual acid / alkali liquor on the surface by using DI pure water; pre-dehydrating the silicon wafer in a slow lifting mode; after the flower basket is placed in the groove, cleaning is conducted for 20 S, slow lifting and inclined pulling opening are conducted, slow lifting and inclined pulling rising are conducted, and inclined pulling closing is conducted after water is discharged. According to the method for solving the problem that the TOPCon battery slice adheres to the slice with the liquid in the alkali polishing process, water cleaning and pre-dehydration of an existing Topcon battery in the alkali polishing process are optimized, the alkali polishing production requirement of the Topcon battery slice can be met, and therefore the effects of batch production of the Topcon battery slice and improvement of the production yield are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of battery slices, and in particular to a method for solving the problem of TOPCon battery slices being sticky with liquid. Background Art

[0002] The TOPCon battery sheet alkali polishing and adhesive stripping method is a method for cleaning battery sheets. With the continuous development of new energy technologies, the use of renewable energy such as solar energy is becoming more and more extensive. As an important energy conversion device, battery sheets play a vital role in photovoltaic systems. The quality of battery sheets directly affects the energy conversion efficiency and operating stability of the entire system. Because Topcon battery sheets have higher battery conversion efficiency, lower production costs, and better technological breakthroughs, with the continuous development of science and technology, people have higher and higher requirements for the manufacturing process of the TOPCon battery sheet alkali polishing and adhesive stripping method.

[0003] The existing battery sheet cleaning has certain drawbacks when used. In the promotion experiment of Topcon cells in high-efficiency flexible crystalline silicon solar cells, how to effectively overcome the technical difficulties of liquid in the production process of battery sheet alkaline polishing, and how to effectively reduce the liquid sticking to the sheet in the alkaline polishing of Topcon cells is a problem that needs in-depth research and urgent solution. The existing alkaline polishing cleaning adopts a single basket 60-piece production mode in the production of sheets to increase the sheet spacing to solve the problem of liquid sticking in the production process. The main impacts of the above solutions are as follows: ① The production capacity is expected to be reduced by more than 30,000 per day; ② The labor of personnel in the poiy process is increased, and the flower baskets are manually moved more than 330 times a day; ③ The cost of rework chemicals and water and electricity is increased. For this reason, we propose a method to solve the problem of liquid sticking to TOPCon battery sheets during alkaline polishing. Summary of the invention

[0004] Technical problem to be solved: In view of the shortcomings of the prior art, the present invention provides a method for solving the problem of sticky liquid on TOPCon battery slices during alkaline polishing, and optimizes the water cleaning and pre-dehydration steps of the existing Topcon battery in the alkaline polishing process. The process of the present application can meet the production needs of Topcon battery slices in alkaline polishing, thereby achieving mass production of Topcon battery slices and improving production yield, which can effectively solve the problems in the background technology.

[0005] Technical solution: To achieve the above purpose, the technical solution adopted by the present invention is: a method for solving the problem of TOPCon battery sheet alkali polishing and adhesive sheet with liquid, which specifically includes the following steps: S1: Pre-cleaning: pre-clean the silicon wafer; S2: Alkali polishing: Use a mixture of sodium hydroxide and alkaline polishing additives to polish the back of the silicon wafer; S3: Post-cleaning: The alkaline polished silicon wafer is placed in a mixed solution of hydrogen peroxide, sodium hydroxide and pure water for cleaning; S4: Pickling: Use a mixed solution of hydrochloric acid + hydrofluoric acid and pure water to pickle the silicon wafer; S5: Water washing: Use DI pure water to wash away impurities and residual acid / alkali solution on the surface; S6: Pre-dehydration: Pre-dehydration of the silicon wafer using a slow extraction method; S7: Slow pull slot logic: After the flower basket is placed in the slot, it is cleaned for 20 seconds, slowly pulled up and opened, slowly pulled up and raised, and closed after the water comes out; S8: Monitoring output: Finally, the surface residual liquid of the cleaned silicon wafer is monitored to check whether there is excessive residual liquid on the surface and output qualified products.

[0006] As a preferred technical solution of the present application, the reaction temperature of water washing in the step S5 is room temperature and the time is 90s.

[0007] As a preferred technical solution of the present application, the bubbling pressure of water washing in the S5 step is 0.3~0.5Mpa, and the bubbling flow rate of water washing is 0.5~1m³ / h.

[0008] As a preferred technical solution of the present application, the post-cleaning temperature in the S6 step is 45±5°C and the cleaning time is 20s.

[0009] As a preferred technical solution of the present application, in the step S6, the robotic arm uses an oblique pulling mode for dehydration, and the oblique pulling angle is 3°.

[0010] As a preferred technical solution of the present application, the slow pulling in step S6 uses a pulling speed of 5 to 10 mm / s.

[0011] As a preferred technical solution of the present application, the slow pull overflow in the S6 step is controlled at cold + hot 1200L / h, and the matching is the set temperature.

[0012] As a preferred technical solution of the present application, in the step S6, after pre-dehydration, the silicon wafer is thoroughly dried using an oven at high temperature.

[0013] As a preferred technical solution of the present application, in the step S6, the oven drying temperature is 95±5°C and the time is 650s.

[0014] As a preferred technical solution of the present application, a residual liquid capacity and quality monitoring system is set in the S8 step, including a residual amount monitoring sensor, a pH acidity monitoring sensor, a central processing unit, a display and a product output controller. The output ends of the residual amount monitoring sensor and the pH acidity monitoring sensor are connected to the input end of the central processing unit, and the output end of the central processing unit is connected to the input end of the display and the product output controller.

[0015] Beneficial effects: Compared with the prior art, the present invention provides a method for solving the problem of TOPCon battery slices sticking to the sheet with liquid during alkali polishing, which has the following beneficial effects: This method for solving the problem of TOPCon battery slices sticking to the sheet with liquid during alkali polishing optimizes the water cleaning and pre-dehydration steps of the existing Topcon battery in the alkali polishing process, and the process of the present application can meet the production needs of Topcon battery slices alkali polishing, thereby achieving mass production of Topcon battery slices and improving the production yield, meeting the technical breakthrough of 120 slices in a single basket of alkali polished slices, and the sticking liquid is reduced from 4.8% in the experiment to below 0.14%; the mechanical arm has an oblique pulling function, and the angle is adjusted by 3°~6°; the slow pulling overflow is controlled at cold + hot 1200L / h±300, and the matching is the set temperature 45±5℃, the entire TOPCon battery slice alkali polishing method has a simple structure, is easy to operate, and has a better effect than the traditional method. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a process flow diagram of a method for solving the problem of TOPCon battery thin film alkali bonding.

[0017] Figure 2 The present invention is a schematic diagram of a countermeasure for improving the problem of TOPCon battery thin film sticking with liquid in a method for solving the problem of TOPCon battery thin film sticking with liquid after alkaline polishing.

[0018] Figure 3 The present invention is a schematic diagram of the oblique pulling structure of a mechanical arm in a method for solving the problem of TOPCon battery sheet alkaline adhesive sheet carrying liquid.

[0019] Figure 4 The present invention is a schematic diagram of overflow bubbling in a method for solving the problem of TOPCon battery thin sheet alkaline adhesive film carrying liquid. DETAILED DESCRIPTION

[0020] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0021] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figure 1-4 As shown, a method for solving the problem of TOPCon battery sheet alkaline adhesive film with liquid, specifically comprising the following steps: S1: Pre-cleaning: pre-clean the silicon wafer; S2: Alkali polishing: Use a mixture of sodium hydroxide and alkaline polishing additives to polish the back of the silicon wafer; S3: Post-cleaning: The alkaline polished silicon wafer is placed in a mixed solution of hydrogen peroxide, sodium hydroxide and pure water for cleaning; S4: Pickling: Use a mixed solution of hydrochloric acid + hydrofluoric acid and pure water to pickle the silicon wafer; S5: Water washing: Use DI pure water to wash away impurities and residual acid / alkali solution on the surface; S6: Pre-dehydration: Pre-dehydration of the silicon wafer using a slow extraction method; S7: Slow pull slot logic: After the flower basket is placed in the slot, it is cleaned for 20 seconds, slowly pulled up and opened, slowly pulled up and raised, and closed after the water comes out; S8: Monitoring output: Finally, the surface residual liquid of the cleaned silicon wafer is monitored to check whether there is excessive residual liquid on the surface and output qualified products.

[0024] The water cleaning and pre-dehydration steps of the alkali polishing process of the existing Topcon battery have been optimized. The process of this application can meet the production needs of alkali polishing of Topcon battery slices, thereby achieving mass production of Topcon battery slices and improving the production yield.

[0025] Furthermore, the reaction temperature of water washing in step S5 is room temperature and the time is 90s.

[0026] Furthermore, in step S5, the bubbling pressure of water cleaning is 0.3~0.5Mpa, and the bubbling flow rate of water cleaning is 0.5~1m³ / h.

[0027] Furthermore, the post-cleaning temperature in step S6 is 45±5° C., and the cleaning time is 20 s.

[0028] Furthermore, in step S6, the robot arm uses an oblique pulling mode for dehydration, and the oblique pulling angle is 3°.

[0029] Furthermore, the slow pulling in step S6 uses a pulling speed of 5 to 10 mm / s.

[0030] Furthermore, in step S6, the slow pull overflow is controlled at cold + hot 1200 L / h, and the matching is the set temperature.

[0031] Furthermore, after the pre-dehydration in step S6, the silicon wafer is thoroughly dried using an oven at high temperature.

[0032] Furthermore, in step S6, the oven drying temperature is 95±5° C. and the time is 650 s.

[0033] Furthermore, in step S8, a residual liquid capacity and quality monitoring system is set up, including a residual amount monitoring sensor, a pH monitoring sensor, a central processing unit, a display and a product output controller. The output ends of the residual amount monitoring sensor and the pH monitoring sensor are connected to the input end of the central processing unit, and the output end of the central processing unit is connected to the input end of the display and the product output controller.

[0034] The experimental data are as follows:

[0035] Working principle: It meets the technical breakthrough of 120 pieces of alkali polishing thin slices in a single basket, and the sticky liquid is reduced from 4.8% in the experiment to below 0.14%; the mechanical arm has the function of inclined pulling, and the angle is adjusted from 3° to 6°; the slow pulling overflow is controlled at cold + hot 1200L / h±300, and the matching is the set temperature of 45±5℃. The water cleaning and pre-dehydration steps of the existing Topcon battery in the alkali polishing process are optimized. The process of this application can meet the production needs of Topcon battery thin slices alkali polishing, thereby achieving the effect of mass production of Topcon battery slices and improving production yield; This application reduces the alkaline polishing process of Topcon battery cell thin slice production with sticky film liquid. Compared with the existing technology, by increasing the overflow bubbling pressure of the water cleaning process and reducing the bubbling flow rate, the bubbling penetration is stronger, and the sticky film separation effect is improved. By increasing the water cleaning temperature of the slow pull tank, increasing the cleaning immersion time, increasing the inclined pulling function of the robot arm flower basket, reducing the overflow of the water tank, and increasing the rising speed of the robot arm, the above core process adjustments are combined to improve the slow pulling and dehydration effect of the silicon wafer, and the sticky film liquid is reduced from 4.8% in the experiment to below 0.14%. The extremely low transformation cost can achieve a breakthrough in the single crystal thinning of the Topcon battery PE route. The production of alkaline polished thin slices is increased from 60 slices per basket to 120 slices per basket, increasing production capacity (50%) and improving the overall yield of Topcon battery cells.

[0036] It should be noted that, in this article, relational terms such as first and second (number one, number two), etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0037] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for solving the problem of TOPCon battery sheet alkali bonding, characterized in that: The specific steps include the following: S1: Pre-cleaning: pre-clean the silicon wafer; S2: Alkali polishing: Use a mixture of sodium hydroxide and alkaline polishing additives to polish the back of the silicon wafer; S3: Post-cleaning: The alkaline polished silicon wafer is placed in a mixed solution of hydrogen peroxide, sodium hydroxide and pure water for cleaning; S4: Pickling: Use a mixed solution of hydrochloric acid + hydrofluoric acid and pure water to pickle the silicon wafer; S5: Water washing: Use DI pure water to wash away impurities and residual acid / alkali solution on the surface; S6: Pre-dehydration: Pre-dehydration of the silicon wafer using a slow extraction method; S7: Slow pull slot logic: After the flower basket is placed in the slot, it is cleaned for 20 seconds, slowly pulled up and opened, slowly pulled up and raised, and closed after the water comes out; S8: Monitoring output: Finally, the surface residual liquid of the cleaned silicon wafer is monitored to check whether there is excessive residual liquid on the surface and output qualified products.

2. A method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: The reaction temperature of water washing in step S5 is room temperature and the time is 90 seconds.

3. A method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: The bubbling pressure of water washing in step S5 is 0.3-0.5 MPa, and the bubbling flow rate of water washing is 0.5-1 m³ / h.

4. A method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: The post-cleaning temperature in step S6 is 45±5° C. and the cleaning time is 20 s.

5. The method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: In the step S6, the robot arm uses an oblique pulling mode for dehydration, and the oblique pulling angle is 3°.

6. A method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: The slow pulling in step S6 uses a pulling speed of 5 to 10 mm / s.

7. The method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: In the step S6, the slow pull overflow is controlled at 1200 L / h of cold + hot, and the matching is the set temperature.

8. The method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: In the step S6, after the pre-dehydration, the silicon wafer is thoroughly dried in an oven at high temperature.

9. The method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: In step S6, the oven drying temperature is 95±5° C. and the drying time is 650 s.

10. The method for solving the problem of TOPCon battery sheet alkali bonding according to claim 1, characterized in that: In the step S8, a residual liquid capacity and quality monitoring system is set up, including a residual amount monitoring sensor, a pH monitoring sensor, a central processing unit, a display and a product output controller. The output ends of the residual amount monitoring sensor and the pH monitoring sensor are connected to the input end of the central processing unit, and the output end of the central processing unit is connected to the input end of the display and the product output controller.

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