Etching equipment

Abstract

The utility model provides etching equipment, relates to the field of photovoltaic technology, and aims to solve the technical problem that the manufacturing process of a photovoltaic cell is tedious. The etching equipment comprises a conveying device and a liquid supply device, the liquid supply device comprises a first liquid supply part and a second liquid supply part which are opposite to each other, and the first liquid supply part and the second liquid supply part are arranged at an interval to form a passage for a photovoltaic cell to pass through; the conveying device is used for driving the photovoltaic cells to pass through the passage; the end face, facing the second liquid supply part, of the first liquid supply part is provided with a first liquid outlet, and the end face, facing the first liquid supply part, of the second liquid supply part is provided with a second liquid outlet. In the first direction, the length of the second liquid outlet is larger than or equal to the preset length, and the length of the first liquid outlet is smaller than the preset length. The preset length refers to the length of the photovoltaic battery piece in the first direction, and the first direction is perpendicular to the conveying direction of the conveying device. The etching equipment is used for asynchronous etching of two surfaces of a photovoltaic cell, and integration of single equipment can be realized while the process flow is reduced.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic technology, and in particular to an etching device. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] In the field of photovoltaic cell manufacturing, the fabrication of back-contact cells requires the formation of different morphologies on the front and back sides of the substrate. For example, a pyramid-shaped textured surface is formed on the front side of the substrate to increase the light absorption of the cell; while a base-shaped polished surface is formed on the back side of the substrate to provide a reaction interface for the subsequent deposition process of P-regions and N-regions.

[0004] In related technologies, wet etching is used to form textured and polished surfaces on the substrate. However, wet etching is non-selective for the substrate. Therefore, forming the double-sided morphology of the substrate requires at least several basic process steps such as texturing, mask deposition, polishing, and mask removal, making the process complicated. Utility Model Content

[0005] The purpose of this invention is to provide an etching device to solve the technical problem of the complicated manufacturing process of photovoltaic cells.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] In a first aspect, this utility model provides an etching device for simultaneously etching two surfaces of a photovoltaic cell. The etching device includes a conveying device and a liquid supply device. The liquid supply device includes a first liquid supply component and a second liquid supply component opposite to each other. The first liquid supply component and the second liquid supply component are spaced apart to form a passage for the photovoltaic cell to pass through.

[0008] The conveying device is used to drive the photovoltaic cells through the passage;

[0009] The end face of the first liquid supply component facing the second liquid supply component has a first liquid outlet, and the end face of the second liquid supply component facing the first liquid supply component has a second liquid outlet.

[0010] In the first direction, the length of the second outlet is greater than or equal to a preset length, and the length of the first outlet is less than the preset length;

[0011] The preset length refers to the length of the photovoltaic cell in a first direction, which is perpendicular to the conveying direction of the conveying device.

[0012] According to at least one embodiment of the present invention, the conveying device includes a driving device and two rollers that are pulverizedly connected to the driving device, with the two rollers respectively abutting against both sides of the photovoltaic cell.

[0013] According to at least one embodiment of the present invention, the two rollers are respectively located on both sides of the passage, and the diameter of the cross-section of the rollers increases along the direction from the second liquid supply member to the first liquid supply member;

[0014] The roller abuts against the side of both the first liquid supply component and the side of the second liquid supply component.

[0015] According to at least one embodiment of the present invention, the first liquid supply component has a cavity for containing a first etching liquid, the first liquid outlet is connected to a portion of the cavity near the bottom wall, and the top wall of the cavity is close to or flush with the end face of the first liquid supply component facing the second liquid supply component.

[0016] According to at least one embodiment of the present invention, the etching apparatus further includes a first pushing device, which is fluidly connected to the cavity.

[0017] According to at least one embodiment of the present invention, the first liquid supply component further has a first channel communicating with the first liquid outlet, and one end of the first channel opposite to the first liquid outlet is connected to the outside of the first liquid supply component.

[0018] According to at least one embodiment of the present invention, the first liquid supply member further includes a rolling element movably disposed in the first liquid outlet, the rolling element dividing the first liquid outlet into a first part communicating with the cavity and a second part communicating with the first channel.

[0019] According to at least one embodiment of the present invention, a portion of the surface of the rolling element is flush with or higher than the end face of the first liquid supply element facing the second liquid supply element; and / or,

[0020] The rolling element is a cylinder.

[0021] According to at least one embodiment of the present invention, a third portion is further formed between the rolling element and the bottom wall of the first liquid outlet, wherein the third portion connects the first portion and the second portion.

[0022] According to at least one embodiment of the present invention, the number of liquid supply devices is multiple, and the multiple liquid supply devices are arranged along the conveying direction of the conveying device;

[0023] The etching apparatus further includes two slide rails, with each of the first liquid supply components slidably disposed on one slide rail and each of the second liquid supply components slidably disposed on the other slide rail.

[0024] According to at least one embodiment of the present invention, the arrangement density of the plurality of liquid supply devices along the conveying direction is first large and then small.

[0025] According to at least one embodiment of the present invention, in a first direction, the midpoints of the first liquid outlet, the second liquid outlet, and the photovoltaic cell are at the same position.

[0026] Secondly, this utility model also provides an etching method, which uses the etching equipment described in the first aspect to simultaneously etch two surfaces of a photovoltaic cell, the method comprising:

[0027] Provided a photovoltaic cell in transit;

[0028] The second etching solution is supplied to the upper surface of the photovoltaic cell through the second outlet of the second liquid supply component, and the extension length of the second etching solution in the first direction is greater than or equal to the preset length.

[0029] The first etching solution is supplied to the lower surface of the photovoltaic cell through the first outlet of the first liquid supply component, and the extension length of the first etching solution in the first direction is less than the preset length.

[0030] According to at least one embodiment of the present invention, the second etching solution is the same as or different from the first etching solution.

[0031] According to at least one embodiment of the present invention, when the second etching solution and the first etching solution are different etching solutions, the second etching solution is a texturing etching solution and the first etching solution is a polishing etching solution.

[0032] According to at least one embodiment of the present invention, when supplying the first etching solution to the lower surface of the photovoltaic cell, the process includes:

[0033] Adjust the supply rate of the first etching solution; and / or improve the wettability of the first etching solution to ensure complete etching of the lower surface of the photovoltaic cell.

[0034] In one or more technical solutions provided in the exemplary embodiments of this utility model, at least one of the following beneficial effects can be achieved.

[0035] The etching apparatus of this exemplary embodiment includes a conveying device and a liquid supply device. The conveying device is used to convey the photovoltaic cell forward and through the passage between the first liquid supply member and the second liquid supply member of the liquid supply device. On the two opposite end faces of the first and second liquid supply members, there are respectively a first liquid outlet and a second liquid outlet. When the photovoltaic cell passes through this passage, its two surfaces are coated with the first etching solution and the second etching solution, respectively. The length of the second liquid outlet is greater than or equal to a preset length of the photovoltaic cell, meaning the second etching solution is coated along the entire preset length of one surface of the photovoltaic cell. During the forward conveying of the photovoltaic cell, the second etching solution can uniformly cover the surface. The length of the first liquid outlet is less than the preset length, allowing the first etching solution to compensate for the edge integrity issues of the photovoltaic cell surface by improving wettability. The difference in length between the first and second liquid outlets allows the etching of both surfaces of the photovoltaic cell to occur simultaneously without interference. Compared to existing technologies, where wet etching is non-selective and requires at least several basic process steps such as texturing, mask deposition, polishing, and mask removal to achieve different morphologies on the two surfaces of a photovoltaic cell, the etching equipment of the present invention can reduce the number of process steps and achieve integration of a single device.

[0036] Furthermore, the etching equipment of the exemplary embodiment of this utility model can maintain the batch processing capacity of the chain wet etching equipment, while achieving the stability of the total amount of reactants per unit area by fixed arrangement and replenishment compared to the tank wet etching equipment, and requires less reaction chemicals and pure water consumption to achieve the same effect. Attached Figure Description

[0037] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification.

[0038] Figure 1 This is a schematic diagram of the overall structure of the etching equipment according to an embodiment of the present invention;

[0039] Figure 2 This is a front view structural schematic diagram of a liquid supply device according to an embodiment of the present utility model;

[0040] Figure 3 This is a top view of the liquid supply device according to an embodiment of the present invention.

[0041] Figure 4 This is a longitudinal cross-sectional view of the liquid supply device according to an embodiment of the present invention.

[0042] Figure 5 This is an isometric structural diagram of the liquid supply device and photovoltaic cell according to an embodiment of the present invention.

[0043] Figure 6 yes Figure 5 A partial structural diagram of part A;

[0044] Figure 7 This is a side view of the liquid supply device according to an embodiment of the present invention.

[0045] Figure 8 yes Figure 7 A partial structural diagram of part B;

[0046] Figure 9 This is a partial structural schematic diagram of a liquid supply device according to another embodiment of the present invention;

[0047] Figure 10 This is a schematic flowchart of an etching method according to an embodiment of the present invention.

[0048] Figure label:

[0049] 10. Liquid supply device; 11. First liquid supply component; 111. First liquid outlet; 111a. First part; 111b. Second part; 111c. Third part; 112. Cavity; 113. First channel; 12. Second liquid supply component; 121. Second liquid outlet;

[0050] 20. Photovoltaic cell; 21. Lower surface; 22. Upper surface;

[0051] 30. Roller; 31. Shaft;

[0052] 40. Rolling parts. Detailed Implementation

[0053] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0054] In the field of photovoltaic cell manufacturing, the two surfaces of the substrate of back contact photovoltaic cells (BC) need to be prepared with different morphologies. For example, the front side (light-receiving surface) needs to form a textured surface with a pyramid shape of a certain size, height and density to increase the light absorption rate of the front side of the photovoltaic cell; the back side needs to form a polished surface composed of a pyramid-shaped morphology of a certain size and quantity to provide a reaction interface for the subsequent deposition of P-regions and N-regions.

[0055] To create textured and polished surfaces on the back contact photovoltaic cells, wet etching processes are employed in related technologies. Wet etching equipment includes two configurations: tank-type and chain-type. Tank-type wet etching equipment is typically used for batch processing, where photovoltaic substrates are loaded into standard substrate cassettes and then placed into different chemical tanks for processing. Tank-type equipment can process multiple substrates simultaneously, making it suitable for applications where production efficiency requirements are not particularly high. Chain-type wet etching equipment, on the other hand, is a continuous processing system where photovoltaic substrates move from one processing tank to another via a conveyor chain, making it suitable for high-volume and highly automated production environments.

[0056] Because wet etching is a non-selective etching process for photovoltaic cell substrates (silicon wafers), neither texturing nor polishing can achieve the desired morphology on only one side. In related technologies, under the manufacturing process of mass production equipment in bonding production lines, achieving different morphologies on both sides of a photovoltaic cell substrate requires at least several basic process steps, including texturing, mask deposition, polishing, and mask removal, which increases the number of steps and extends the process time.

[0057] The etching apparatus provided in this exemplary embodiment uses a single etching device with two different etching solution supply components to simultaneously etch the upper and lower surfaces of a photovoltaic cell, thereby achieving different morphologies on both sides at the same time. By setting the length of the outlet of one of the two supply components to be less than the preset length of the photovoltaic cell, the etching solutions on the upper and lower surfaces do not interfere with each other, maintaining the stability of the etching reaction interface between the upper and lower surfaces. This shortens the fabrication process of photovoltaic cells with different morphologies on both sides and integrates it into a single device, reducing etching solution consumption while retaining the core batch processing capability of a chain wet etching apparatus.

[0058] Figure 5 This is an isometric structural diagram of the liquid supply device and photovoltaic cell according to an embodiment of the present invention. Figure 7 This is a side view of the liquid supply device according to an embodiment of the present invention. Figure 5 and Figure 7As shown, the etching apparatus of an exemplary embodiment of the present invention includes a conveying device and a liquid supply device 10. The liquid supply device 10 includes a first liquid supply member 11 and a second liquid supply member 12 facing each other. The first liquid supply member 11 and the second liquid supply member 12 are spaced apart to form a passage for the photovoltaic cell 20 to pass through. The conveying device is used to drive the photovoltaic cell 20 through the passage. The end face of the first liquid supply member 11 facing the second liquid supply member 12 has a first liquid outlet 111, and the end face of the second liquid supply member 12 facing the first liquid supply member 11 has a second liquid outlet 121. In a first direction, the length of the second liquid outlet 121 is greater than or equal to a preset length, and the length of the first liquid outlet 111 is less than the preset length. The preset length refers to the length of the photovoltaic cell 20 in the first direction, which is perpendicular to the conveying direction of the conveying device.

[0059] In practical applications, multiple conveying devices and liquid supply devices 10 are arrayed along the conveying direction of the photovoltaic cells 20, such as... Figure 3 and Figure 4 As shown, where, Figure 3 This is a top view of the liquid supply device according to an embodiment of the present invention. Figure 4 This is a longitudinal cross-sectional view of the liquid supply device according to an embodiment of the present invention. Driven by the conveying device, when the photovoltaic cell 20 passes through the passage, that is, through the gap between the relatively disposed first liquid supply component 11 and second liquid supply component 12, the second etching liquid supplied by the second liquid supply component 12 through the second liquid outlet 121 coats the upper surface 22 of the photovoltaic cell 20, and the first etching liquid supplied by the first liquid supply component 11 through the first liquid outlet 111 coats the lower surface 21 of the photovoltaic cell 20.

[0060] When the length of the second outlet 121 in the first direction is greater than or equal to the preset length of the photovoltaic cell 20, the second etching solution is coated along the entire length of the upper surface 22 of the photovoltaic cell 20 in the first direction. Combined with the forward conveying of the photovoltaic cell 20, the second etching solution can be uniformly coated across its entire upper surface 22. Correspondingly, the length of the first outlet 111 in the first direction is less than the preset length of the photovoltaic cell 20. That is, the edge of the lower surface 21 of the photovoltaic cell 20 is not opposite to the first outlet 111. The length of the first outlet 111 in the first direction is narrowed, for example, slightly less than the preset length. This prevents the first etching solution from rising to the upper surface 22 of the photovoltaic cell 20 due to surface tension, thus avoiding interference with the etching reaction interface of the upper surface 22. This allows for etching effects on different morphologies of the upper surface 22 and lower surface 21 of the photovoltaic cell 20.

[0061] In some embodiments, the midpoints of the first liquid outlet 111, the second liquid outlet 121, and the photovoltaic cell 20 are aligned in the first direction. That is, the edge of the first liquid outlet 111 is equidistant from the corresponding edge of the photovoltaic cell 20 in the first direction; the edge of the second liquid outlet 121 is equidistant from the corresponding edge of the photovoltaic cell 20 in the first direction. This allows the first and second etching solutions to be uniformly coated on the lower surface 21 and upper surface 22 of the photovoltaic cell 20, respectively.

[0062] For example, the second etching solution may be the same as or different from the first etching solution. When the second etching solution is different from the first etching solution, the second etching solution may be a texturing etching solution, and the first etching solution may be a polishing etching solution.

[0063] For example, the second etching solution is an alkaline solution or an acidic solution to form a textured surface on the upper surface 22 of the photovoltaic cell 20, and the first etching solution includes surfactants, reaction speed-up / speed-down agents, viscosity modifiers, defoaming agents, etc. to form a polished surface on the lower surface 21 of the photovoltaic cell 20.

[0064] Since the second etching solution is on the upper surface 22 of the photovoltaic cell 20, even if the etched reaction solution partially diffuses to the lower surface 21 under the influence of gravity, it has little effect on the polished surface of the lower surface 21. This is because the reverse texturing process of the polished surface of the photovoltaic cell 20 is very difficult. Specifically, compared with the original silicon wafer, the semi-finished wafer after polishing has a smaller density of surface sites (silicon-oxygen single bonds) that can combine with hydroxide ions on its exposed crystal surface during the texturing process. Therefore, the rate at which the texturing additive combines and completely covers the silicon wafer surface decreases rapidly, making the process of forming a uniform textured surface relatively more difficult. The first etching solution can easily affect the texturing process of the upper surface 22 of the photovoltaic cell 20. Therefore, the first etching solution etches the photovoltaic cell 20 from below, and the first outlet 111 is narrowed. The second etching solution etches the photovoltaic cell 20 from above, so that the first etching solution is less likely to spread from the side of the photovoltaic cell 20 to the upper surface 22 of the photovoltaic cell 20, and thus it is less likely to affect the texturing of the photovoltaic cell 20.

[0065] In some embodiments, the length of the first liquid outlet 111 in the first direction is less than the preset length of the photovoltaic cell 20 because the first outlet 111 is narrowed. Various embodiments can be implemented to maintain the etching effect at the edge of the lower surface 21 of the photovoltaic cell 20.

[0066] For example, the supply rate of the first etching solution can be increased so that the first etching solution can diffuse to the edge of the lower surface 21 after being supplied from the first outlet 111.

[0067] For example, the contact area of ​​the etching solution can be increased by increasing the wettability of the first etching solution. For instance, by adjusting the content of surfactant components in the first etching solution, the wetting effect of the first etching solution at the solid-liquid interface is greater than that at the gas-liquid interface, that is, increasing the wetting angle of the first etching solution at the contact reaction interface. Optionally, the content of viscosity control agent components in the first etching solution can be adjusted to increase the surface tension of the first etching solution and further reduce the wetting angle at the gas-liquid interface. This allows the first etching solution to diffuse to the edge of the lower surface 21 of the photovoltaic cell 20 after being supplied from the first outlet 111 to the lower surface 21.

[0068] In another optional embodiment, on the etching equipment, a jet nozzle is provided on both sides of the passage of the liquid supply device 10. The two jet nozzles are respectively directed toward the two side edges of the lower surface 21 of the photovoltaic cell 20 in the first direction. The jet of the jet nozzle is also the first etching liquid. For example, each jet nozzle is connected to a container storing the first etching liquid through a pumping device and corresponding pipeline, so that the first etching liquid can be spread all over the lower surface 21 of the photovoltaic cell 20 to maintain the integrity of the reaction interface.

[0069] Figure 6 yes Figure 5 A schematic diagram of the partial structure of part A. (See attached diagram.) Figure 5 and Figure 6 As shown in the exemplary embodiment of the present invention, the etching apparatus includes a conveying device and two rollers 30 that are connected to the driving device in a transmission manner. The two rollers 30 respectively abut against both sides of the photovoltaic cell 20.

[0070] For example, the driving device can be a motor, which drives two rollers 30 to rotate via a corresponding shaft 31. The shaft 31 is arranged vertically on both sides of the photovoltaic cell 20, and the two rollers 30 abut against the two sides of the photovoltaic cell 20, and drive the photovoltaic cell 20 forward along the conveying direction through friction. In this process, the end face of the first liquid supply component 11 facing the second liquid supply component 12 can also serve to support the photovoltaic cell 20.

[0071] Continue as Figure 5 As shown, the two rollers 30 in the conveying device can be located at any position in the conveying direction, or they can be located on both sides of the passage. The diameter of the cross-section of the roller 30 increases along the direction from the second liquid supply component 12 to the first liquid supply component 11. The roller 30 abuts against the side of the first liquid supply component 11 and the side of the second liquid supply component 12.

[0072] When the length of the second liquid supply port of the second liquid supply component 12 is greater than the preset length, the side of the second liquid supply component 12, the side of the photovoltaic cell 20, and the side of the first liquid supply component 11 form a gradient structure that narrows inward in sequence. By setting the cross-section of the roller 30 to a frustum-shaped structure with a smaller top and a larger bottom, the outer surface of the roller 30 can abut against the side of the second liquid supply component 12, the side of the photovoltaic cell 20, and the side of the first liquid supply component 11. On the one hand, this structure of the roller 30 can transport the photovoltaic cell 20 forward; on the other hand, this roller 30 is set on both sides of the passage, that is, on both sides of the first liquid outlet 111 and the second liquid outlet 121. At this position, the second etching liquid on the upper surface 22 and the first etching liquid on the lower surface 21 can be physically isolated, so that the etching of different surfaces of the photovoltaic cell 20 does not interfere with each other.

[0073] Figure 8 yes Figure 7 A schematic diagram of the partial structure of part B. (See attached diagram.) Figure 7 and Figure 8 As shown, the first liquid supply component 11 has a cavity 112 for containing the first etching liquid, the first liquid outlet 111 is connected to the part of the cavity 112 near the bottom wall, and the top wall of the cavity 112 is close to or flush with the end face of the first liquid supply component 11 facing the second liquid supply component 12.

[0074] Since the first outlet 111 of the first liquid supply component 11 provides the first etching solution to the lower surface 21 of the photovoltaic cell 20 from bottom to top, the surface of the etching solution may fluctuate due to gravity. Utilizing the principle of communicating vessels, the first etching solution is pre-stored in the cavity 112. Because the top wall of the cavity 112 is close to or flush with the end face of the first liquid supply component 11 facing the second liquid supply component 12, and the first outlet 111 is connected to the cavity 112 near its bottom, the liquid surface of the first outlet 111 is flush with the liquid surface of the cavity 112. When the photovoltaic cell 20 passes through the first outlet 111, a first pushing device, such as a peristaltic pump or gear pump, fluidly connected to the cavity 112, applies pressure to the liquid in the cavity 112. At this time, the first etching solution in the first outlet 111 is affected by both surface tension and gravity, forming a reaction interface with good contact with the first etching solution on the lower surface 21 of the photovoltaic cell 20. Based on this, the setting of the cavity 112 reduces the violent fluctuations of the first etching solution at the first outlet 111, which is conducive to the formation of a good etching reaction interface.

[0075] For example, a rolling element 40 is movably disposed in the first liquid outlet 111. The rolling element 40 is in clearance fit with the first liquid outlet 111. For example, the rolling element 40 is a cylinder. The first etching liquid is pumped out from the gap between the first liquid outlet 111 and the rolling element 40. For example, the liquid level of the first etching liquid is 1mm to 5mm higher than the top surface of the first liquid outlet 111.

[0076] For example, a portion of the surface of the rolling element 40 is flush with or higher than the end face of the first liquid supply element 11 facing the second liquid supply element 12. In this embodiment, on the one hand, the rolling element 40 can supply the first etching liquid to the lower surface 21 of the photovoltaic cell 20 in a vortex manner, which is conducive to the transportation of the first etching liquid and the discharge of the etching reaction liquid; on the other hand, the rolling element 40 can also serve as a rolling support for the photovoltaic cell 20, thereby facilitating the smooth transport of the photovoltaic cell 20.

[0077] Figure 9 This is a partial structural schematic diagram of a liquid supply device according to another embodiment of the present invention. (See attached diagram.) Figure 9 As shown, the first liquid supply component 11 also has a first channel 113 communicating with the first liquid outlet 111, and one end of the first channel 113 away from the first liquid outlet 111 is connected to the outside of the first liquid supply component 11.

[0078] The first channel 113 extends downward from one end of the first liquid outlet 111 and connects to the outside of the first liquid supply component 11. Since the density of the etching product formed by the photovoltaic cell 20 and the first etching solution is greater than the density of the first etching solution, the etching product at the first liquid outlet 111 will settle under the action of gravity and be smoothly discharged through the first channel 113. This facilitates the supply of new first etching solution from the first liquid outlet 111 to maintain a good etching reaction interface on the lower surface 21 of the photovoltaic cell 20.

[0079] Continue as Figure 9 As shown, the first liquid supply component 11 also has a rolling element 40 movably disposed in the first liquid outlet 111, the rolling element 40 dividing the first liquid outlet 111 into a first part 111a communicating with the cavity 112 and a second part 111b communicating with the first channel 113.

[0080] In practical applications, the cavity 112 is connected to the first part 111a of the first outlet 111 near the top of the first outlet 111, and the first channel 113 is connected to the second part 111b of the first outlet 111 near the bottom of the first outlet 111. The first etching solution in the cavity 112 enters from the top of the first outlet 111 through the corresponding connection passage, and is coated onto the lower surface 21 of the photovoltaic cell 20 through the rolling element 40 from the top of the first outlet 111. The reactants generated after the etching reaction are driven by the rolling element 40 and under their own gravity, they settle to the bottom of the first outlet 111 and are discharged from the first supply element 11 through the first channel 113, thereby realizing the discharge of waste liquid. Based on this, the first liquid outlet 111 is divided into a first part 111a and a second part 111b by the rolling element 40. The first etching liquid enters the first part 111a closer to the photovoltaic cell 20, and the second part 111b discharges the etching reactant further away from the photovoltaic cell 20, so that the first liquid supply element 11 can more smoothly complete the delivery of the first etching liquid and the discharge of the etching reactant.

[0081] In some embodiments, a third portion 111c is formed between the rolling element 40 and the bottom wall of the first outlet 111, wherein the third portion 111c connects the first portion 111a and the second portion 111b.

[0082] Since there may be disturbance at the contact interface when the liquid surface at the first outlet 111 is pumped, the excess liquid of the first etching solution in the first part 111a is discharged from the first channel 113 through the second part 111b via the third part 111c below the rolling element 40, thereby forming a relatively stable liquid surface to form a stable etching reaction interface with the photovoltaic cell 20.

[0083] When a portion of the surface of the rolling element 40 is flush with or higher than the end face of the first liquid supply element 11 facing the second liquid supply element 12, the rolling element 40 can also assist in the transmission of the photovoltaic cell 20.

[0084] It is understandable that the structure of the second liquid supply component 12 can be exactly the same as that of the first liquid supply component 11. The structure of the second liquid supply component 12 can also be different from that of the first liquid supply component 11. For example, the second liquid outlet 121 of the second liquid supply component 12 is a slit formed on the second liquid supply component 12. The second etching liquid is pumped to the slit by a pump provided outside the second liquid supply component 12, and supplied to the upper surface 22 of the photovoltaic cell 20 from the opening of the end face of the second liquid supply component 12 toward the first liquid supply component 11, so as to carry out the etching reaction to form a textured surface.

[0085] like Figure 3 and Figure 4As shown, there are multiple liquid supply devices 10, which are arranged along the conveying direction of the conveying device; the etching equipment also includes two slide rails, with each first liquid supply component 11 slidably disposed on one slide rail and each second liquid supply component 12 slidably disposed on the other slide rail.

[0086] Since the arrangement density of the liquid supply device 10 affects the etching accuracy of the photovoltaic cell 20, in order to control the etching of the photovoltaic cell 20, the position of the liquid supply device 10, which consists of the first liquid supply component 11 and the second liquid supply component 12, in the conveying direction is controlled by the controller to control the etching reaction time. For example, the arrangement density of the liquid supply device 10 along the conveying direction is first large and then small, thereby adjusting the supply frequency of the first and second etching solutions in the early, middle and late stages of the etching reaction, thereby controlling the size and density of the morphology of the upper surface 22 and the lower surface 21 of the photovoltaic cell 20 and maintaining the stability of the etching effect.

[0087] To maintain the stability of the movement of the first liquid supply component 11 and the second liquid supply component 12, two sliders are respectively provided on the two sides of the first liquid supply component 11 at locations away from the second liquid supply component 12, and the two sliders are slidably mounted on two parallel slide rails; the second liquid supply component 12 is slidably mounted on two other parallel slide rails, and two sliders are respectively provided on the two sides of the second liquid supply component 12 at locations away from the first liquid supply component 11, and the two sliders are slidably mounted on the other two parallel slide rails. It can be understood that all four slide rails extend along the conveying direction of the photovoltaic cell 20.

[0088] Figure 1 This is a schematic diagram of the overall structure of the etching equipment according to an embodiment of the present invention; Figure 2 This is a front view structural schematic diagram of a liquid supply device according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, a single etching device has an array of four rows of liquid supply devices 10 along the first direction, which means that four photovoltaic cells 20 can be processed in parallel at the same time to improve production efficiency.

[0089] An exemplary embodiment of this utility model also provides an etching method, which uses the etching equipment described in the above embodiment to simultaneously etch two surfaces of the photovoltaic cell 20.

[0090] Figure 10 This is a schematic flowchart of an etching method according to an embodiment of the present invention. Figure 10 As shown, the etching method includes the following steps:

[0091] Step 1001: Provide a photovoltaic cell 20 being transported.

[0092] The photovoltaic cells 20 to be processed are placed in the basket clamp and fed through the feeding area, then through the pre-cleaning area and into the texturing-polishing area.

[0093] Step 1002: A second etching solution is supplied to the upper surface 22 of the photovoltaic cell 20 through the second outlet 121 of the second liquid supply component 12, and the extension length of the second etching solution in the first direction is greater than or equal to a preset length; a first etching solution is supplied to the lower surface 21 of the photovoltaic cell 20 through the first outlet 111 of the first liquid supply component 11, and the extension length of the first etching solution in the first direction is less than a preset length.

[0094] The photovoltaic cell 20 to be processed is conveyed to the liquid supply device 10 array via the roller 30 of the transmission device. When passing through the passage between the first liquid supply component 11 and the second liquid supply component 12 in the liquid supply device 10, the second liquid supply component 12 coats the upper surface 22 of the photovoltaic cell 20 with a second etching liquid for texturing and controls the corresponding temperature. At the same time, the first liquid supply component 11 coats the lower surface 21 of the photovoltaic cell 20 with a first etching liquid for polishing and controls the corresponding temperature, thereby achieving the double-sided asynchronous etching effect of the upper surface 22 and the lower surface 21 of the photovoltaic cell 20.

[0095] After the photovoltaic cell 20 is etched by the liquid supply device 10 array, the photovoltaic cell 20 can enter the post-processing process, such as post-cleaning, dehydration and drying.

[0096] When the first etching solution is supplied to the lower surface 21 of the photovoltaic cell 20, since the length of the first outlet 111 of the first liquid supply member 11 is less than the preset length of the photovoltaic cell 20, in order to maintain the etching integrity of the entire lower surface 21 of the photovoltaic cell 20, the supply rate of the first etching solution or the wettability of the first etching solution can be increased so that the first etching solution can diffuse to the edge of the lower surface 21 after being supplied from the first outlet 111 to the lower surface 21.

[0097] like Figure 7 and Figure 8 As shown, when the photovoltaic cell 20 passes through the first liquid outlet 111, a first pushing device, such as a peristaltic pump or gear pump, which is fluidly connected to the cavity 112, applies a certain pressure to the liquid in the cavity 112. At this time, the first etching solution in the first liquid outlet 111 is affected by both surface tension and gravity, forming a reaction interface with good contact with the first etching solution on the lower surface 21 of the photovoltaic cell 20. Increasing the pressure of the first pushing device can increase the supply rate of the first etching solution; conversely, decreasing the pressure can reduce the supply rate of the first etching solution.

[0098] The technical advantages of the above etching method compared to the prior art are the same as those of the above etching equipment, and will not be repeated here.

[0099] Those skilled in the art should understand that the above embodiments are merely for clearly illustrating the present invention and are not intended to limit the scope of the present invention. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present invention.

Claims

1. An etching apparatus, characterized in that, For simultaneous etching of two surfaces of a photovoltaic cell, the etching equipment includes a conveying device and a liquid supply device. The liquid supply device includes a first liquid supply element and a second liquid supply element opposite to each other. The first liquid supply element and the second liquid supply element are spaced apart to form a passage for the photovoltaic cell to pass through. The conveying device is used to drive the photovoltaic cells through the passage; The end face of the first liquid supply component facing the second liquid supply component has a first liquid outlet, and the end face of the second liquid supply component facing the first liquid supply component has a second liquid outlet. In the first direction, the length of the second outlet is greater than or equal to a preset length, and the length of the first outlet is less than the preset length; The preset length refers to the length of the photovoltaic cell in a first direction, which is perpendicular to the conveying direction of the conveying device.

2. The etching apparatus according to claim 1, characterized in that, The conveying device includes a driving device and two rollers that are connected to the driving device in a transmission manner. The two rollers respectively abut against both sides of the photovoltaic cell.

3. The etching apparatus according to claim 2, characterized in that, The two rollers are located on opposite sides of the passage, and the diameter of the cross-section of the rollers increases along the direction from the second liquid supply element to the first liquid supply element; The roller abuts against the side of both the first liquid supply component and the side of the second liquid supply component.

4. The etching apparatus according to claim 1, characterized in that, The first liquid supply component has a cavity for containing a first etching liquid, the first liquid outlet is connected to the portion of the cavity near the bottom wall, and the top wall of the cavity is close to or flush with the end face of the first liquid supply component facing the second liquid supply component.

5. The etching apparatus according to claim 4, characterized in that, The etching apparatus further includes a first pushing device, which is fluidly connected to the cavity.

6. The etching apparatus according to claim 4, characterized in that, The first liquid supply component also has a first channel communicating with the first liquid outlet, and one end of the first channel opposite to the first liquid outlet is connected to the outside of the first liquid supply component.

7. The etching apparatus according to claim 6, characterized in that, The first liquid supply component also has a rolling element movably disposed in the first liquid outlet, the rolling element dividing the first liquid outlet into a first part communicating with the cavity and a second part communicating with the first channel.

8. The etching apparatus according to claim 7, characterized in that, A portion of the surface of the rolling element is flush with or higher than the end face of the first liquid supply element facing the second liquid supply element; and / or, The rolling element is a cylinder.

9. The etching apparatus according to claim 7, characterized in that, A third portion is formed between the rolling element and the bottom wall of the first outlet, wherein the third portion connects the first portion and the second portion.

10. The etching apparatus according to any one of claims 1-9, characterized in that, The number of liquid supply devices is multiple, and the multiple liquid supply devices are arranged along the conveying direction of the conveying device; The etching apparatus further includes two slide rails, with each of the first liquid supply components slidably disposed on one slide rail and each of the second liquid supply components slidably disposed on the other slide rail; and / or The arrangement density of the multiple liquid supply devices along the conveying direction is initially high and then decreases; and / or, In the first direction, the midpoints of the first liquid outlet, the second liquid outlet, and the photovoltaic cell are aligned.

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