TOPCon battery silicon wafer cleaning device
By setting up two main cleaning tanks and a secondary recycling tank in the TOPCon battery silicon wafer cleaning device, the chemical solution can be recycled, solving the problem of high chemical consumption in the texturing process, reducing costs and improving the cleaning effect.
Patent Information
- Application Number
- CN202422675437.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-11-01
AI Technical Summary
In the current TOPCon battery manufacturing process, the texturing process uses a large amount of cleaning agents, resulting in high production costs. How to reduce chemical consumption while ensuring cleaning cleanliness is an urgent problem to be solved.
Two main cleaning tanks are used, with a secondary recycling tank in between. The chemical solution in the second main tank is recovered and reused in the first main tank, increasing the utilization rate of the chemical solution. By setting up a secondary recycling tank between the two main tanks, the chemical solution can be recycled.
It significantly reduced the consumption of cleaning solution, improved the cleaning effect, reduced production costs, and ensured that the impurity content on the surface of the cleaned silicon wafers met production requirements.
Smart Images
Figure CN223486997U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of new energy battery technology, and in particular to a TOPCon battery silicon wafer cleaning device. Background Technology
[0002] In the fabrication process of TOPCon cells, silicon wafers typically require a texturing process. This process involves the silicon wafers passing through the following tanks in sequence: cleaning tank → texturing tank → alkaline cleaning tank → acid cleaning tank → slow lifting tank → drying tank. The cleaning tank primarily uses alkali and hydrogen peroxide as chemicals. The strong oxidizing properties of hydrogen peroxide oxidize organic matter on the silicon wafer surface, while the alkali dissolves the oxidation products, removing residual organic matter. During the silicon ingot cutting process, significant cutting marks, microcracks, and some residual organic matter remain on the surface of the wafer, with a damaged layer thickness of approximately 3-5 μm. These need to be effectively removed using the solubility of alkali and the strong oxidizing properties of hydrogen peroxide. After cleaning, the silicon wafers enter the texturing tank for texturing, forming a pyramidal textured surface. Currently, the texturing process uses a large amount of cleaning agents, leading to high production costs. How to reduce the consumption of chemicals on the production line while ensuring cleaning cleanliness is a pressing issue that needs to be addressed. Utility Model Content
[0003] The purpose of this invention is to provide a TOPCon battery silicon wafer cleaning device, which uses two main cleaning tanks and sets up a recovery auxiliary tank between the two main tanks to recover the chemical solution in the downstream main tank and discharge it to the upstream main tank for reuse, thereby increasing the utilization rate of the chemical solution and reducing costs.
[0004] To achieve the above objectives, this utility model provides the following technical solution:
[0005] This utility model discloses a TOPCon battery silicon wafer cleaning device, comprising a first main tank, a recycling auxiliary tank, and a second main tank, wherein:
[0006] The first main tank includes a first outer tank body and a first inner tank body disposed within and communicating with the first outer tank body; the first outer tank body is connected to the recycling sub-tank via a first connecting pipe; the second main tank includes a second outer tank body and a second inner tank body disposed within and communicating with the second outer tank body; the second outer tank body is connected to the recycling sub-tank via a second connecting pipe.
[0007] A further embodiment: The first main tank further includes a first circulation pipe disposed at the bottom of the first inner tank, and the first outer tank and the first inner tank are connected through the first circulation pipe; the second main tank further includes a second circulation pipe disposed at the bottom of the second inner tank, and the second outer tank and the second inner tank are connected through the second circulation pipe.
[0008] A further solution: both the first and second circulation pipes have uniformly formed flow holes.
[0009] A further solution: The second connecting pipe includes a three-way pipe and a three-way valve. The first end of the three-way pipe is connected to the recycling sub-tank, the second end is connected to the bottom of the second outer tank, and the third end is connected to the ground pipe.
[0010] A further embodiment: the upper edge height of the first outer tank is higher than the upper edge height of the first inner tank; the upper edge height of the second outer tank is higher than the upper edge height of the second inner tank.
[0011] A further solution: An overflow pipe is connected to the upper part of the recycling sub-tank.
[0012] A further solution: a first replenishment pipe is provided between the first outer tank and the first inner tank; a second replenishment pipe is provided between the second outer tank and the second inner tank.
[0013] A further option is to have at least two first replenishment tubes and at least two second replenishment tubes.
[0014] Compared with the prior art, the beneficial effects of this utility model are:
[0015] This invention adds a main cleaning tank and a secondary recycling tank between the two main tanks, allowing the cleaning solution in the second main tank to be recycled back to the first main tank for reuse. This reduces the consumption of cleaning solution, significantly improves the utilization rate, and thus effectively controls costs. The main impurities on the silicon wafer surface have dissolved in the first main tank, and the cleaning solution in the second main tank is relatively clean, therefore it can be recycled and reused. Testing showed that the impurity content and conductivity of the returned cleaning solution using ICP-MS and ICP-OES were consistent with conventional cleaning solutions, meeting the production requirements of composite production lines.
[0016] In addition, the two-step cleaning of silicon wafers significantly improves the cleaning effect compared to the original one-step cleaning method, reducing the probability of surface defects in the subsequent texturing process. Attached Figure Description
[0017] Figure 1 This is a perspective view of the present utility model;
[0018] Figure 2 This is a top view of the present invention;
[0019] Figure 3 This is the front view of the present utility model;
[0020] In the diagram: 1-First main tank, 11-First outer tank, 12-First inner tank, 13-First circulation pipe, 2-Recovery auxiliary tank, 21-Overflow pipe, 3-Second main tank, 31-Second outer tank, 32-Second inner tank, 33-Second circulation pipe, 4-First connecting pipe, 5-Second connecting pipe, 51-Tee pipe, 52-Tee valve, 6-First replenishment pipe, 7-Second replenishment pipe. Detailed Implementation
[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0022] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0023] Please see Figures 1-3 In this embodiment, a TOPCon battery silicon wafer cleaning device includes a first main tank 1 located away from the texturing tank, a recycling auxiliary tank 2, and a second main tank 3 located near the texturing tank, connected in sequence, wherein:
[0024] The first main tank 1 includes a first outer tank body 11 and a first inner tank body 12 disposed within and connected to the first outer tank body 11; the first outer tank body 11 is connected to the recycling auxiliary tank 2 via a first connecting pipe 4; the second main tank 3 includes a second outer tank body 31 and a second inner tank body 32 disposed within and connected to the second outer tank body 31; the second outer tank body 32 is connected to the recycling auxiliary tank 2 via a second connecting pipe 5. Silicon wafers are placed in a basket and first placed in the first main tank 1 for cleaning to remove surface grease residue and some surface loss layers. Then, the basket is removed and placed in the second main tank 3 for cleaning, forming an oxide layer on the silicon wafer surface. This facilitates more even application of the texturing solution to the silicon wafer surface, promoting pyramid nucleation. The cleaning solution in the second cleaning tank 3 is discharged into the recycling auxiliary tank 2 via the second connecting pipe 5, and then returned to the first cleaning tank 1 via the first connecting pipe 4 for continued use.
[0025] Because the cleaning tanks primarily use alkali and hydrogen peroxide to clean the original silicon wafers and do not contain other metal ions, tests have shown that the impurity content and conductivity of the returned cleaning solution (ICP-MS and ICP-OES) are consistent with those of conventional cleaning solutions, meeting the production requirements of the composite production line. It is particularly important to note that the cleaning solutions in the first main tank (1) and the second main tank (3) need to be completely drained and replaced with fresh solutions periodically. Generally, the production line is stopped for solution replacement after cleaning a certain number of silicon wafers (800-1500 baskets).
[0026] Furthermore, both the first circulation pipe 13 and the second circulation pipe 33 have uniformly opened flow holes, which guide the liquid in the outer tank into the inner tank, realizing the liquid circulation between the inner and outer tanks.
[0027] Furthermore, the upper edge height of the first outer groove 11 is higher than the upper edge height of the first inner groove 12; the upper edge height of the second outer groove 31 is higher than the upper edge height of the second inner groove 32.
[0028] Furthermore, a first replenishment pipe 6 is provided between the first outer tank 11 and the first inner tank 12, through which the medicine flows into the first outer tank 11.
[0029] Furthermore, the first main tank 1 also includes a first circulation pipe 13 located at the bottom of the first inner tank 12, and the first outer tank 11 and the first inner tank 12 are connected through the first circulation pipe 13; the second main tank 3 also includes a second circulation pipe 33 located at the bottom of the second inner tank 32, and the second outer tank 31 and the second inner tank 32 are connected through the second circulation pipe 33. The liquid medicine enters from the first outer tank 11, flows into the first circulation pipe 13 under the action of the motor, and then enters the first inner tank 12 through the flow holes opened on the first circulation pipe 13. The liquid level in the first inner tank 12 continuously rises, overflows after filling, and flows into the first outer tank 11. The liquid medicine in the second outer tank 31 is extracted through the second connecting pipe 5 (built-in water pump) and collected in the recovery auxiliary tank 2.
[0030] Furthermore, an overflow pipe 21 is connected to the upper part of the recovery sub-tank 2 to ensure that the liquid level in the recovery sub-tank 2 is kept within a safe range.
[0031] Furthermore, the second connecting pipe 5 includes a three-way pipe 51 and a three-way valve 52. The first end of the three-way pipe 51 is connected to the recovery auxiliary tank 2, the second end is connected to the bottom of the second outer tank 32, and the third end is connected to the ground pipe (not shown in the figure). During normal production, the valve at the second end is open and the valve at the third end is closed. During liquid change, the valve at the second end is closed and the valve at the third end is open, and the waste liquid is discharged into the ground pipe. After the liquid level in the recovery auxiliary tank 2 rises to a certain level, the recovered medicine is pumped into the first outer tank 11 through the first connecting pipe 4 (built-in water pump). After being circulated by the first circulation pipe 13, it flows into the first inner tank 12 and mixes evenly with the original medicine in the first inner tank 12. At the same time, the first replenishment pipe 6 is provided between the first outer tank 11 and the first inner tank 12, and the self-replenished medicine enters the first outer tank 11 through the first replenishment pipe 6. When the medicine overflows from the first inner tank 12, it flows into the first outer tank 11, forming a circulation.
[0032] Furthermore, there are two first replenishment tubes 6, one for hydrogen peroxide and the other for alkali solution; similarly, there are two second replenishment tubes 7, one for hydrogen peroxide and the other for alkali solution.
[0033] In operation, the silicon wafers are carried in a basket and first placed into the first main tank 1 for cleaning for a few seconds, then removed and placed into the second main tank 3 for cleaning for a few seconds. Since the amount of chemical solution in the tanks is lost after each cleaning, it needs to be replenished periodically. Two second replenishment pipes 7 are used to replenish alkali solution and hydrogen peroxide, respectively, and the concentration of the chemical solution in the second replenishment pipes 7 is the same as the concentration in the second main tank 1. During the interval when the basket is lifted from the second main tank 3, a certain amount of chemical solution is discharged into the recovery auxiliary tank 2 via the second connecting pipe 5. When the liquid level in the recovery auxiliary tank 2 reaches a certain height, it begins to be replenished into the first main tank 1 through the first connecting pipe 4 during the basket lifting interval. Since the hydrogen peroxide concentration in the first main tank 1 is lower than that in the second main tank 3, the second replenishment pipe 6 does not need to replenish hydrogen peroxide; it only needs to replenish alkali solution quantitatively. The alkali solution concentrations in the first main tank 1 and the second main tank 2 are approximately the same, and the hydrogen peroxide concentration in the second main tank 3 is about twice that of the first main tank 1. The replenishment amount each time is equal to the average amount of chemical solution lost after each basket cleaning.
[0034] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
[0035] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.
Claims
1. A TOPCon battery silicon wafer cleaning device, characterized in that, It includes a first main tank (1), a secondary recycling tank (2), and a second main tank (3), wherein: The first main tank (1) includes a first outer tank body (11) and a first inner tank body (12) disposed within and connected to the first outer tank body (11); the first outer tank body (11) is connected to the recycling sub-tank (2) through a first connecting pipe (4); the second main tank (3) includes a second outer tank body (31) and a second inner tank body (32) disposed within and connected to the second outer tank body (31); the second outer tank body (31) is connected to the recycling sub-tank (2) through a second connecting pipe (5).
2. The TOPCon battery silicon wafer cleaning device according to claim 1, characterized in that, The first main tank (1) further includes a first circulation pipe (13) disposed at the bottom of the first inner tank (12), and the first outer tank (11) and the first inner tank (12) are connected through the first circulation pipe (13); the second main tank (3) further includes a second circulation pipe (33) disposed at the bottom of the second inner tank (32), and the second outer tank (31) and the second inner tank (32) are connected through the second circulation pipe (33).
3. The TOPCon battery silicon wafer cleaning device according to claim 2, characterized in that, Both the first circulation pipe (13) and the second circulation pipe (33) have uniformly opened flow holes.
4. The TOPCon battery silicon wafer cleaning device according to claim 1, characterized in that, The second connecting pipe (5) includes a three-way pipe (51) and a three-way valve (52). The first end of the three-way pipe (51) is connected to the recycling sub-tank (2), the second end is connected to the bottom of the second outer tank body (31), and the third end is connected to the ground pipe.
5. The TOPCon battery silicon wafer cleaning apparatus according to claim 1, characterized in that, The upper edge height of the first outer groove (11) is higher than the upper edge height of the first inner groove (12); the upper edge height of the second outer groove (31) is higher than the upper edge height of the second inner groove (32).
6. The TOPCon battery silicon wafer cleaning apparatus according to claim 1, characterized in that, An overflow pipe (21) is connected to the upper part of the recycling sub-tank (2).
7. The TOPCon battery silicon wafer cleaning apparatus according to claim 1, characterized in that, A first replenishment pipe (6) is provided between the first outer tank (11) and the first inner tank (12); a second replenishment pipe (7) is provided between the second outer tank (31) and the second inner tank (32).
8. The TOPCon battery silicon wafer cleaning apparatus according to claim 7, characterized in that, The number of the first replenishment tube (6) is at least two; the number of the second replenishment tube (7) is at least two.