A device for reducing acid consumption in the removal of bsg

Abstract

The utility model discloses a kind of equipment of removing BSG acid consumption, including water film area and main groove cleaning area, wafer is carried out assembly line conveying on water film area and main groove process area by liquid roller, water film area is provided with water film valve support, water film inductor, water film water replenishing pipe, water film valve, water replenishing bucket, water inlet pipe, thermostatic mixing valve, cold water inlet pipe and hot water inlet pipe, the one end of water film water replenishing pipe is connected with multiple water film needles of water spraying by water film valve, the other end of water film water replenishing pipe is communicated with the water outlet of water replenishing bucket, the water inlet of water replenishing bucket is communicated with water inlet pipe, water inlet pipe is communicated with cold water inlet pipe and hot water inlet pipe by thermostatic mixing valve. The utility model need not to reconstruct the tank body inside of main groove cleaning area, also need not to additionally add heating system, just can reduce the dosage of hydrofluoric acid, and need not to use high concentration hydrofluoric acid, with the advantages of process optimization cost low, high yield.

Description

Technical Field

[0001] This utility model belongs to the technical field of solar cell processing equipment, specifically relating to a device for reducing BSG acid consumption. Background Technology

[0002] The key technology of TOPCon cells involves fabricating an ultrathin layer of silicon oxide on the back of the cell, followed by the deposition of a thin layer of doped silicon. These two layers together form a passivated contact structure, effectively reducing surface recombination and metal-to-metal recombination, thereby improving the conversion efficiency of the solar cell.

[0003] BSG (borosilicate glass) is produced during the boron diffusion process in the fabrication of TOPCon cells. It has good chemical stability and certain insulation properties, and can play a role in protecting the PN junction in subsequent processes. It can also be removed by solutions such as hydrofluoric acid.

[0004] The removal of the BSG layer is primarily achieved using chain cleaning equipment. The BSG removal process requires the use of hydrofluoric acid to clean and remove BSG from the back and edges of the silicon wafer, preparing it for the subsequent alkaline polishing process. Using existing BSG removal equipment, the hydrofluoric acid used in the BSG removal process accounts for approximately one-quarter of the total hydrofluoric acid used in the solar cell manufacturing process, resulting in very high hydrofluoric acid consumption and costs. To reduce the company's non-silicon costs, it is urgent to reduce the amount of hydrofluoric acid used, necessitating optimization and cost reduction of the BSG removal process.

[0005] Furthermore, the current process temperature inside the BSG removal chain tank on the production line is ambient temperature. The low reaction rate between hydrofluoric acid and silicon wafers means that hydrofluoric acid at low concentrations cannot achieve the desired BSG removal. A high concentration of hydrofluoric acid is required to achieve the desired BSG removal. However, using high-concentration hydrofluoric acid results in some of it not being used effectively, leading to waste. Utility Model Content

[0006] In view of the problem that existing BSG removal equipment has high acid consumption, the purpose of this utility model is to provide a device for BSG removal that reduces acid consumption.

[0007] The present invention achieves the aforementioned technical effect through the following technical solution.

[0008] This invention provides a device for reducing BSG acid consumption, including a water film area for forming a water film on the front side of a silicon wafer and a main tank cleaning area for cleaning BSG from the back side and edges of the silicon wafer. The silicon wafer is conveyed in a production line on the water film area and the main tank process area via liquid-laden rollers. The water film area is equipped with a water film valve support above the silicon wafer, a water film sensor at the starting end of the water film area for sensing the position of the silicon wafer, a water film replenishment pipe connected to the water film valve support, a water film valve, a replenishment tank, an inlet pipe, a thermostatic mixing valve, a cold water inlet pipe, and a hot water inlet pipe. One end of the water film replenishment pipe is connected to multiple water film needles that spray water through the water film valve, and the other end of the water film replenishment pipe is connected to the outlet of the replenishment tank. The inlet of the replenishment tank is connected to the inlet pipe, and the inlet pipe is connected to the cold water inlet pipe and the hot water inlet pipe through the thermostatic mixing valve.

[0009] Furthermore, a liquid level sensor is installed inside the water replenishment tank.

[0010] Furthermore, the BSG removal and acid consumption reduction device also includes a controller, and the water film valve and the thermostatic mixing valve are both solenoid valves. The water film valve, the thermostatic mixing valve, the water film sensor, and the liquid level sensor are all electrically connected to the controller.

[0011] Furthermore, the water film valve support is perpendicular to the conveying direction of the silicon wafer.

[0012] Furthermore, the water film valve bracket is provided with two sets of water film valves arranged side by side. One end of each set of water film valves is connected to the water film replenishment pipe, and the other end of each set of water film valves is connected to multiple water film needles.

[0013] Furthermore, the water film needles are evenly spaced along the length of the water film valve support, and the aperture of the water film needles is 0.5~5mm.

[0014] Furthermore, the water film area and the main tank cleaning area are seamlessly connected by liquid-laden rollers.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] This invention utilizes hot water to treat silicon wafers in a water film area. After a hot water film is formed on the front side of the silicon wafer, the silicon wafer carries the hot water film into the main cleaning tank. The hot water film raises the temperature of the hydrofluoric acid in the tank from room temperature. At this time, the liquid-carrying rollers in the tank carry the hydrofluoric acid and attach it to the back side and edges of the silicon wafer. The temperature brought by the hot water film promotes the reaction between the hydrofluoric acid and the BSG layer on the back side and edges of the silicon wafer, thereby achieving the purpose of removing the BSG layer on the back side and edges.

[0017] This invention can increase the process temperature in the tank without modifying the interior of the main cleaning area or adding a heating system, thereby promoting the reaction rate of hydrofluoric acid with the BSG layer on the back and edge of the silicon wafer, thus reducing the amount of hydrofluoric acid used. It also eliminates the need for high-concentration hydrofluoric acid, resulting in low process optimization costs and high returns. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 is a schematic diagram of the structure of the device for reducing BSG acid consumption according to an embodiment of this application.

[0020] Figure 2 is a schematic diagram of the pipeline connection in the water film area according to an embodiment of this application.

[0021] Figure 3 is a schematic diagram of the electrical connections of the controller according to an embodiment of this application.

[0022] In the diagram: 1-Silicon wafer, 2-Water film area, 2.1-Water film valve bracket, 2.2-Water film sensor, 2.3-Water film replenishment pipe, 2.4-Water film valve, 2.5-Replenishment tank, 2.6-Inlet pipe, 2.7-Thermostatic mixing valve, 2.8-Cold water inlet pipe, 2.9-Hot water inlet pipe, 2.10-Level sensor, 2.11-Water film needle, 3-Main tank cleaning area, 4-Roller with liquid, 5-Controller. Detailed Implementation

[0023] To make the technical problems solved, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments. It should be understood that the embodiments described herein are only some, not all, of the embodiments of this utility model, and are merely used to explain the present utility model and are not intended to limit the present utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] like Figures 1-3 As shown, this application embodiment provides a device for reducing BSG acid consumption, including a water film area 2 for forming a water film on the front side of a silicon wafer 1 and a main tank cleaning area 3 for cleaning the BSG on the back side and edges of the silicon wafer 1. The silicon wafer 1 is conveyed in a production line on the water film area 2 and the main tank cleaning area 3 via liquid-carrying rollers 4. The water film area 2 is provided with a water film valve support 2.1 located above the silicon wafer 1, a water film sensor 2.2 located at the starting end of the water film area 2 for sensing the position of the silicon wafer 1, a water film replenishment pipe 2.3 connected to the water film valve support 2.1, a water film valve 2.4, a replenishment tank 2.5, a water inlet pipe 2.6, a thermostatic mixing valve 2.7, a cold water inlet pipe 2.8, and a hot water inlet pipe 2.9. One end of the water film replenishment pipe 2.3 is connected to multiple water film needles 2.11 that spray water through the water film valve 2.4, and the other end of the water film replenishment pipe 2.3 is connected to the outlet of the water replenishment tank 2.5; the inlet of the water replenishment tank 2.5 is connected to the inlet pipe 2.6, and the inlet pipe 2.6 is connected to the cold water inlet pipe 2.8 and the hot water inlet pipe 2.9 through the thermostatic mixing valve 2.7.

[0026] As a specific implementation scheme, a liquid level sensor 2.10 is installed inside the water replenishment tank 2.5. In this way, the water level in the water replenishment tank 2.5 can be monitored by the liquid level sensor 2.10, and when the water replenishment tank 2.5 reaches a low liquid level, the thermostatic mixing valve 2.7 can be opened to replenish water.

[0027] As a specific implementation scheme, the BSG removal and acid consumption reduction equipment also includes a controller 5, and the water film valve 2.4 and the thermostatic mixing valve 2.7 are both solenoid valves. The water film valve 2.4, the thermostatic mixing valve 2.7, the water film sensor 2.2, and the liquid level sensor 2.10 are all electrically connected to the controller 5. Thus, through the controller 5, when the silicon wafer 1 passes the water film sensor 2.2, the water film valve 2.4 automatically opens, and the water film needle 2.11 sprays water to form a hot water film on the front side of the silicon wafer 1; when the water replenishment tank 2.5 reaches a low liquid level, the thermostatic mixing valve 2.7 automatically opens, and the cold water inlet pipe 2.8 and the hot water inlet pipe 2.9 simultaneously inject water into the water replenishment tank 2.5 according to the set water temperature.

[0028] In one specific implementation, the water film valve bracket 2.1 is perpendicular to the conveying direction of the silicon wafer 1. This allows water to be sprayed onto the front side of the silicon wafer 1 to form a hot water film.

[0029] As a specific implementation scheme, the water film valve bracket 2.1 is provided with two sets of water film valves 2.4 arranged side by side. One end of each set of water film valves 2.4 is connected to the water film replenishment pipe 2.3, and the other end of each set of water film valves 2.4 is connected to multiple water film needles 2.11. In this way, a more uniform water film can be formed on the front side of the silicon wafer 1.

[0030] As a specific implementation scheme, the water film needles 2.11 are evenly spaced along the length of the water film valve support 2.1. The aperture of the water film needles 2.11 is 0.5~5mm, specifically 0.5mm, 1mm, 1.5mm, 2.2mm, 3mm, 3.6mm, 4mm, 4.3mm, or 5mm. This ensures more uniform water spraying from the water film needles 2.11, resulting in a more uniform water film formation on the front side of the silicon wafer 1.

[0031] In one specific implementation scheme, the water film area 2 and the main tank cleaning area 3 are seamlessly connected by liquid-carrying rollers 4. Thus, when the hot water film formed on the front side of the silicon wafer is brought into the main tank cleaning area 3, the hot water film uses the temperature difference to raise the temperature of the hydrofluoric acid from room temperature to 40-45°C. At this time, the liquid-carrying rollers in the tank carry the hydrofluoric acid up and attach it to the back side and edges of the silicon wafer. The temperature brought by the hot water film promotes the reaction between the hydrofluoric acid and the BSG layer on the back side and edges of the silicon wafer, achieving the purpose of removing the BSG layer on the back side and edges.

[0032] Working principle: Through controller 5, when the water supply tank 2.5 reaches a low level, the thermostatic mixing valve 2.7 opens. Cold water from the cold water inlet pipe 2.8 and hot water from the hot water inlet pipe 2.9 are mixed according to the set water temperature and then enter the water supply tank 2.5 through the inlet pipe 2.6. At this time, the water supply tank 2.5 provides hot water to the water film supply pipe 2.3. When silicon wafer 1 passes the water film sensor 2.2, the water film valve 2.4 automatically opens, and the water film supply pipe 2.3 delivers hot water to the water film needle 2.1 via the water film valve 2.4. 1. Water is sprayed to form a hot water film on the front side of silicon wafer 1. Hot water is also sprayed in the water film area 2. The hot water film and hot water are carried by the silicon wafer 1 into the main cleaning area 3 through the liquid roller 4. Utilizing the temperature difference, the hot water film and hot water raise the temperature of hydrofluoric acid from room temperature to 40~45℃. At this time, the liquid roller 4 in the tank carries the hydrofluoric acid and attaches it to the back side and edge of silicon wafer 1. The temperature brought by the hot water film and hot water promotes the reaction between hydrofluoric acid and the BSG layer on the back side and edge of silicon wafer 1, thereby achieving the purpose of removing the BSG layer on the back side and edge.

[0033] It should be noted that the technical features of the water film valve and thermostatic mixing valve, water film sensor, liquid level sensor and controller involved in this application should be regarded as prior art. The specific structure, working principle and possible control method and spatial arrangement of these technical features can be adopted by conventional choices in the field and should not be regarded as the inventive point of this utility model patent. This utility model patent will not be further elaborated in detail.

[0034] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the substance and scope of the present invention. Various modifications made by those skilled in the art to the above embodiments after reading this specification are all within the scope of protection of the present invention.

Claims

1. An apparatus for reducing BSG acid consumption, comprising a water film region (2) for forming a water film on the front side of a silicon wafer (1) and a main tank cleaning region (3) for cleaning BSG from the back side and edges of the silicon wafer (1), wherein the silicon wafer (1) is conveyed in a production line on the water film region (2) and the main tank cleaning region (3) via liquid-carrying rollers (4), characterized in that, The water film area (2) is provided with a water film valve bracket (2.1) located above the silicon wafer (1), a water film sensor (2.2) located at the starting end of the water film area (2) and used to sense the position of the silicon wafer (1), a water film water supply pipe (2.3) connected to the water film valve bracket (2.1), a water film valve (2.4), a water supply tank (2.5), a water inlet pipe (2.6), a thermostatic mixing valve (2.7), a cold water inlet pipe (2.8), and a hot water inlet pipe (2.9). .9), one end of the water film replenishment pipe (2.3) is connected to multiple water film needles (2.11) through the water film valve (2.4), the other end of the water film replenishment pipe (2.3) is connected to the outlet of the water replenishment tank (2.5), the inlet of the water replenishment tank (2.5) is connected to the inlet pipe (2.6), and the inlet pipe (2.6) is connected to the cold water inlet pipe (2.8) and the hot water inlet pipe (2.9) through the thermostatic mixing valve (2.7).

2. The device for removing BSG and reducing acid consumption according to claim 1, characterized in that, The water replenishment tank (2.5) is equipped with a liquid level sensor (2.10).

3. The device for removing BSG and reducing acid consumption according to claim 2, characterized in that, It also includes a controller (5), the water film valve (2.4) and the thermostatic mixing valve (2.7) are both solenoid valves, and the water film valve (2.4) and the thermostatic mixing valve (2.7), the water film sensor (2.2) and the liquid level sensor (2.10) are all electrically connected to the controller (5).

4. The device for removing BSG and reducing acid consumption according to claim 1, characterized in that, The water film valve support (2.1) is perpendicular to the conveying direction of the silicon wafer (1).

5. The device for removing BSG and reducing acid consumption according to claim 4, characterized in that, The water film valve bracket (2.1) is provided with two sets of water film valves (2.4) arranged side by side. One end of each set of water film valves (2.4) is connected to the water film water supply pipe (2.3), and the other end of each set of water film valves (2.4) is connected to multiple water film needles (2.11).

6. The device for removing BSG and reducing acid consumption according to claim 5, characterized in that, The water film needles (2.11) are arranged at equal intervals along the length of the water film valve support (2.1), and the aperture of the water film needles (2.11) is 0.5~5mm.

7. The device of claim 1, wherein, The water film area (2) and the main tank cleaning area (3) are seamlessly connected by liquid-laden rollers (4).

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